When using `schedule_code_upgrade` to change the code of a parachain in
the relay chain runtime, we had already fixed to not set the `GoAhead`
signal. This was done to not brick any parachain after the upgrade,
because they were seeing the signal without having any upgrade prepared.
The remaining problem is that the parachain code is only upgraded after
a parachain header was enacted, aka the parachain made some progress.
However, this is quite complicated if the parachain is bricked (which is
the most common scenario why to manually schedule a code upgrade). Thus,
this pull request replaces `SetGoAhead` with `UpgradeStrategy` to signal
to the logic kind of strategy want to use. The strategies are either
`SetGoAheadSignal` or `ApplyAtExpectedBlock`. `SetGoAheadSignal` sets
the go ahead signal as before and awaits a parachain block.
`ApplyAtExpectedBlock` schedules the upgrade and applies it directly at
the `expected_block` without waiting for the parachain to make any kind
of progress.

Fix "double-weights" for extrinsics, use only the ones benchmarked in
the runtime.

Deprecate extrinsics that don't specify WeightLimit, remove their usage
across the repo.

---------

Signed-off-by: Adrian Catangiu <[email protected]>
Co-authored-by: command-bot <>

Rejoice! Rejoice! The story is nearly over.

This PR removes stale migrations, auxiliary structures, and package
dependencies, thus making Rococo and Westend totally free from any
`im-online`-related stuff.

`im-online` still stays a part of the Substrate node and its runtime:
https://github.com/paritytech/polkadot-sdk/blob/0d932484/substrate/bin/node/runtime/src/lib.rs#L2276-L2277
I'm not sure if it makes sense to remove it from there considering that
we're not removing `im-online` from FRAME. Please share your opinion.

Runtime release 1.2 includes bumping of the ParachainHost APIs up to
v10, so let's move all the released APIs out of vstaging folder, this PR
does not include any logic changes only renaming of the modules and some
moving around.

Signed-off-by: Alexandru Gheorghe <[email protected]>

Test started failing after
https://github.com/paritytech/polkadot-sdk/commit/66051adb


which enabled approval coalescing, that was expected to happen because
the test required an polkadot_parachain_approval_checking_finality_lag
of 0, which can't happen with max_approval_coalesce_count greater than 1
because we always delay the approval for no_show_duration_ticks/2 in
case we can coalesce it with other approvals.


So relax a bit the restrictions, since we don't actually care that the
lags are 0, but the fact the finalities are progressing and are not
stuck.

Signed-off-by: Alexandru Gheorghe <[email protected]>

fixes https://github.com/paritytech/polkadot-sdk/issues/3886

---------

Signed-off-by: Andrei Sandu <[email protected]>

The metric records the current protocol_version of the validator that
just connected with the peer_map.len(), which contains all peers that
connected, that has the effect the metric will be wrong since it won't
tell us how many peers we have connected per version because it will
always record the total number of peers

Fix this by counting by version inside peer_map, additionally because
that might be a bit heavier than len(), publish it only on-active
leaves.

---------

Signed-off-by: Alexandru Gheorghe <[email protected]>

Closes: https://github.com/paritytech/polkadot-sdk/issues/3906

Removes transient code introduced to clean up offchain database after
`im-online` pallet removal.

Should be merged after #2290 has been enacted.

Somehow https://github.com/paritytech/polkadot-sdk/pull/3795 was merged
but tests are failing now on master. I suspect that CI is not even
running these tests anymore which is a big issue.

---------

Signed-off-by: Andrei Sandu <[email protected]>

# Description

Since the binary split additional syscalls are getting blocked in
relation to the workers.

With the hardened systemd file it shows the following warning:

```
Cannot fully enable landlock, a Linux kernel security feature. Running validation of malicious PVF code has a higher risk of compromising this machine. Consider upgrading the kernel version for maximum security. status=Ok(NotEnforced) abi=1
```

For it to work we need to allow additionally:
- mount
- umount2
- pivot_root

and set `RestrictNamespaces=false`

Added new line `SystemCallFilter=pivot_root` because otherwise it would
get blocked by ~\@\privileged

Co-authored-by: s0me0ne-unkn0wn <[email protected]>
Co-authored-by: Bastian Köcher <[email protected]>

This PR adds a new extrinsic `Call::restore_ledger ` gated by
`StakingAdmin` origin that restores a corrupted staking ledger. This
extrinsic will be used to recover ledgers that were affected by the
issue discussed in
https://github.com/paritytech/polkadot-sdk/issues/3245.

The extrinsic will re-write the storage items associated with a stash
account provided as input parameter. The data used to reset the ledger
can be either i) fetched on-chain or ii) partially/totally set by the
input parameters of the call.

In order to use on-chain data to restore the staking locks, we need a
way to read the current lock in the balances pallet. This PR adds a
`InspectLockableCurrency` trait and implements it in the pallet
balances. An alternative would be to tightly couple staking with the
pallet balances but that's inelegant (an example of how it would look
like in [this
branch](https://github.com/paritytech/polkadot-sdk/tree/gpestana/ledger-badstate-clean_tightly)).

More details on the type of corruptions and corresponding fixes
https://hackmd.io/DLb5jEYWSmmvqXC9ae4yRg?view#/

We verified that the `Call::restore_ledger` does fix all current
corrupted ledgers in Polkadot and Kusama. You can verify it here
https://hackmd.io/v-XNrEoGRpe7APR-EZGhOA.

**Changes introduced**
- Adds `Call::restore_ledger ` extrinsic to recover a corrupted ledger;
- Adds trait `frame_support::traits::currency::InspectLockableCurrency`
to allow external pallets to read current locks given an account and
lock ID;
- Implements the `InspectLockableCurrency` in the pallet-balances.
- Adds staking locks try-runtime checks
(https://github.com/paritytech/polkadot-sdk/issues/3751)

**Todo**
- [x] benchmark `Call::restore_ledger`
- [x] throughout testing of all ledger recovering cases
- [x] consider adding the staking locks try-runtime checks to this PR
(https://github.com/paritytech/polkadot-sdk/issues/3751)
- [x] simulate restoring all ledgers
(https://hackmd.io/Dsa2tvhISNSs7zcqriTaxQ?view) in Polkadot and Kusama
using chopsticks -- https://hackmd.io/v-XNrEoGRpe7APR-EZGhOA

Related to https://github.com/paritytech/polkadot-sdk/issues/3245
Closes https://github.com/paritytech/polkadot-sdk/issues/3751

---------

Co-authored-by: command-bot <>

This will make it possible to use remaining weight on idle for
processing enqueued messages.
More context here https://github.com/paritytech/polkadot-sdk/issues/3709

---------

Co-authored-by: Adrian Catangiu <[email protected]>

This works only for collators that implement the `collator_fn` allowing
`collation-generation` subsystem to pull collations triggered on new
heads.

Also enables
`request_v2::CollationFetchingResponse::CollationWithParentHeadData` for
test adder/undying collators.

TODO:
- [x] fix tests
- [x] new tests
- [x] PR doc

---------

Signed-off-by: Andrei Sandu <[email protected]>

`execute` and `send` try to decode the xcm in the parameters before
reaching the filter line.
The new extrinsics decode only after the filter line.
These should be used instead of the old ones.

## TODO
- [x] Tests
- [x] Generate weights
- [x] Deprecation issue ->
https://github.com/paritytech/polkadot-sdk/issues/3771
- [x] PRDoc
- [x] Handle error in pallet-contracts

This would make writing XCMs in PJS Apps more difficult, but here's the
fix for that: https://github.com/polkadot-js/apps/pull/10350.
Already deployed! https://polkadot.js.org/apps/#/utilities/xcm

Supersedes https://github.com/paritytech/polkadot-sdk/pull/1798/

---------

Co-authored-by: PG Herveou <[email protected]>
Co-authored-by: command-bot <>
Co-authored-by: Adrian Catangiu <[email protected]>

This is a long due chore ...

---------

Signed-off-by: Andrei Sandu <[email protected]>
Co-authored-by: ordian <[email protected]>

Fixes #3826.

The docs on the `candidates` field of `BlockEntry` were incorrectly
stating that they are sorted by core index. The (incorrect) optimization
was introduced in #3747 based on this assumption. The actual ordering is
based on `CandidateIncluded` events ordering in the runtime. We revert
this optimization here.

- [x] verify the underlying issue
- [x] add a regression test

---------

Co-authored-by: Bastian Köcher <[email protected]>

The PR provides API for obtaining:
- the weight required to execute an XCM message,
- a list of acceptable `AssetId`s for message execution payment,
- the cost of the weight in the specified acceptable `AssetId`.

It is meant to address an issue where one has to guess how much fee to
pay for execution. Also, at the moment, a client has to guess which
assets are acceptable for fee execution payment.
See the related issue
https://github.com/paritytech/polkadot-sdk/issues/690.
With this API, a client is supposed to query the list of the supported
asset IDs (in the XCM version format the client understands), weigh the
XCM program the client wants to execute and convert the weight into one
of the acceptable assets. Note that the client is supposed to know what
program will be executed on what chains. However, having a small
companion JS library for the pallet-xcm and xtokens should be enough to
determine what XCM programs will be executed and where (since these
pallets compose a known small set of programs).
```Rust
pub trait XcmPaymentApi<Call>
	where
		Call: Codec,
	{
		/// Returns a list of acceptable payment assets.
		///
		/// # Arguments
		///
		/// * `xcm_version`: Version.
		fn query_acceptable_payment_assets(xcm_version: Version) -> Result<Vec<VersionedAssetId>, Error>;
		/// Returns a weight needed to execute a XCM.
		///
		/// # Arguments
		///
		/// * `message`: `VersionedXcm`.
		fn query_xcm_weight(message: VersionedXcm<Call>) -> Result<Weight, Error>;
		/// Converts a weight into a fee for the specified `AssetId`.
		///
		/// # Arguments
		///
		/// * `weight`: convertible `Weight`.
		/// * `asset`: `VersionedAssetId`.
		fn query_weight_to_asset_fee(weight: Weight, asset: VersionedAssetId) -> Result<u128, Error>;
		/// Get delivery fees for sending a specific `message` to a `destination`.
		/// These always come in a specific asset, defined by the chain.
		///
		/// # Arguments
		/// * `message`: The message that'll be sent, necessary because most delivery fees are based on the
		///   size of the message.
		/// * `destination`: The destination to send the message to. Different destinations may use
		///   different senders that charge different fees.
		fn query_delivery_fees(destination: VersionedLocation, message: VersionedXcm<()>) -> Result<VersionedAssets, Error>;
	}
```
An
[example](https://gist.github.com/PraetorP/4bc323ff85401abe253897ba990ec29d)
of a client side code.

---------

Co-authored-by: Francisco Aguirre <[email protected]>
Co-authored-by: Adrian Catangiu <[email protected]>
Co-authored-by: Daniel Shiposha <[email protected]>

This PR notifies broker pallet for any parachain slot swaps performed on
the relay chain. This is achieved by registering an `OnSwap` for the the
`coretime` pallet. The hook sends XCM message to the broker chain and
invokes a new extrinsic `swap_leases` which updates `Leases` storage
item (which keeps the legacy parachain leases).

I made two assumptions in this PR:
1.
[`Leases`](https://github.com/paritytech/polkadot-sdk/blob/4987d798/substrate/frame/broker/src/lib.rs#L120)
in `broker` pallet and
[`Leases`](https://github.com/paritytech/polkadot-sdk/blob/4987d798

/polkadot/runtime/common/src/slots/mod.rs#L118)
in `slots` pallet are in sync.
2. `swap_leases` extrinsic from `broker` pallet can be triggered only by
root or by the XCM message from the relay chain. If not - the extrinsic
will generate an error and do nothing.

As a side effect from the changes `OnSwap` trait is moved from
runtime/common/traits.rs to runtime/parachains. Otherwise it is not
accessible from `broker` pallet.

Closes https://github.com/paritytech/polkadot-sdk/issues/3552

TODOs:

- [x] Weights
- [x] Tests

---------

Co-authored-by: command-bot <>
Co-authored-by: eskimor <[email protected]>
Co-authored-by: Bastian Köcher <[email protected]>

Here we add the ability to save subsystem benchmark results in JSON
format to display them as graphs

To draw graphs, CI team will use
[github-action-benchmark](https://github.com/benchmark-action/github-action-benchmark).
Since we are using custom benchmarks, we need to prepare [a specific
data
type](https://github.com/benchmark-action/github-action-benchmark?tab=readme-ov-file#examples):
```
[
    {
        "name": "CPU Load",
        "unit": "Percent",
        "value": 50
    }
]
```

Then we'll get graphs like this: 

![example](https://raw.githubusercontent.com/rhysd/ss/master/github-action-benchmark/main.png)

[A live page with
graphs](https://benchmark-action.github.io/github-action-benchmark/dev/bench/)

---------

Co-authored-by: ordian <[email protected]>

**Update:** Pushed additional changes based on the review comments.

**This pull request fixes various spelling mistakes in this
repository.**

Most of the changes are contained in the first **3** commits:

- `Fix spelling mistakes in comments and docs`

- `Fix spelling mistakes in test names`

- `Fix spelling mistakes in error messages, panic messages, logs and
tracing`

Other source code spelling mistakes are separated into individual
commits for easier reviewing:

- `Fix the spelling of 'authority'`

- `Fix the spelling of 'REASONABLE_HEADERS_IN_JUSTIFICATION_ANCESTRY'`

- `Fix the spelling of 'prev_enqueud_messages'`

- `Fix the spelling of 'endpoint'`

- `Fix the spelling of 'children'`

- `Fix the spelling of 'PenpalSiblingSovereignAccount'`

- `Fix the spelling of 'PenpalSudoAccount'`

- `Fix the spelling of 'insufficient'`

- `Fix the spelling of 'PalletXcmExtrinsicsBenchmark'`

- `Fix the spelling of 'subtracted'`

- `Fix the spelling of 'CandidatePendingAvailability'`

- `Fix the spelling of 'exclusive'`

- `Fix the spelling of 'until'`

- `Fix the spelling of 'discriminator'`

- `Fix the spelling of 'nonexistent'`

- `Fix the spelling of 'subsystem'`

- `Fix the spelling of 'indices'`

- `Fix the spelling of 'committed'`

- `Fix the spelling of 'topology'`

- `Fix the spelling of 'response'`

- `Fix the spelling of 'beneficiary'`

- `Fix the spelling of 'formatted'`

- `Fix the spelling of 'UNKNOWN_PROOF_REQUEST'`

- `Fix the spelling of 'succeeded'`

- `Fix the spelling of 'reopened'`

- `Fix the spelling of 'proposer'`

- `Fix the spelling of 'InstantiationNonce'`

- `Fix the spelling of 'depositor'`

- `Fix the spelling of 'expiration'`

- `Fix the spelling of 'phantom'`

- `Fix the spelling of 'AggregatedKeyValue'`

- `Fix the spelling of 'randomness'`

- `Fix the spelling of 'defendant'`

- `Fix the spelling of 'AquaticMammal'`

- `Fix the spelling of 'transactions'`

- `Fix the spelling of 'PassingTracingSubscriber'`

- `Fix the spelling of 'TxSignaturePayload'`

- `Fix the spelling of 'versioning'`

- `Fix the spelling of 'descendant'`

- `Fix the spelling of 'overridden'`

- `Fix the spelling of 'network'`

Let me know if this structure is adequate.

**Note:** The usage of the words `Merkle`, `Merkelize`, `Merklization`,
`Merkelization`, `Merkleization`, is somewhat inconsistent but I left it
as it is.

~~**Note:** In some places the term `Receival` is used to refer to
message reception, IMO `Reception` is the correct word here, but I left
it as it is.~~

~~**Note:** In some places the term `Overlayed` is used instead of the
more acceptable version `Overlaid` but I also left it as it is.~~

~~**Note:** In some places the term `Applyable` is used instead of the
correct version `Applicable` but I also left it as it is.~~

**Note:** Some usage of British vs American english e.g. `judgement` vs
`judgment`, `initialise` vs `initialize`, `optimise` vs `optimize` etc.
are both present in different places, but I suppose that's
understandable given the number of contributors.

~~**Note:** There is a spelling mistake in `.github/CODEOWNERS` but it
triggers errors in CI when I make changes to it, so I left it as it
is.~~

Fixes formatting for
https://github.com/paritytech/polkadot-sdk/pull/3698

Adds availability-write regression tests.
The results for the `availability-distribution` subsystem are volatile,
so I had to reduce the precision of the test.

https://github.com/paritytech/polkadot-sdk/issues/3742

Related to
https://github.com/paritytech/parity-bridges-common/issues/2538

This PR doesn't contain any functional changes. 

The PR moves specific bridged chain definitions from
`bridges/primitives` to `bridges/chains` folder in order to facilitate
the migration of the `parity-bridges-repo` into `polkadot-sdk` as
discussed in https://hackmd.io/LprWjZ0bQXKpFeveYHIRXw?view

Apart from this it also includes some cosmetic changes to some
`Cargo.toml` files as a result of running `diener workspacify`.

Fixes https://github.com/paritytech/polkadot-sdk/issues/3762 .

---------

Co-authored-by: eskimor <[email protected]>
Co-authored-by: Adrian Catangiu <[email protected]>

Currently `transfer_assets` from pallet-xcm covers 4 main different
transfer types:
- `localReserve`
- `DestinationReserve`
- `Teleport`
- `RemoteReserve`

For the first three, the local execution and the remote message sending
are separated, and fees are deducted in pallet-xcm itself:
https://github.com/paritytech/polkadot-sdk/blob/3410dfb3

/polkadot/xcm/pallet-xcm/src/lib.rs#L1758.

For the 4th case `RemoteReserve`, pallet-xcm is still relying on the
xcm-executor itself to send the message (through the
`initiateReserveWithdraw` instruction). In this case, if delivery fees
need to be charged, it is not possible to do so because the
`jit_withdraw` mode has not being set.

This PR proposes to still use the `initiateReserveWithdraw` but
prepending a `setFeesMode { jit_withdraw: true }` to make sure delivery
fees can be paid.

A test-case is also added to present the aforementioned case

---------

Co-authored-by: Adrian Catangiu <[email protected]>

We do not need to make these traits generic over QueryId type, we can
just use the QueryId alias everywhere

Make sure explicitly set by the operator public addresses go first in
the authority discovery DHT records.

Also update `Discovery` behavior to eliminate duplicates in the returned
addresses.

This PR should improve situation with
https://github.com/paritytech/polkadot-sdk/issues/3519.

Obsoletes https://github.com/paritytech/polkadot-sdk/pull/3657.

Good day,

I'm seeking to add the following bootnodes for Kusama and Polkadot's
relay and system chains. The following commands can be used to test
connectivity. All node keys are backed up.

Polkadot:
```
polkadot --chain polkadot --base-path /tmp/node --name "Boot" --reserved-only --reserved-nodes "/dns/boot-polkadot.luckyfriday.io/tcp/443/wss/p2p/12D3KooWAdyiVAaeGdtBt6vn5zVetwA4z4qfm9Fi2QCSykN1wTBJ" --no-hardware-benchmarks
```


Assethub-Polkadot:

```
polkadot-parachain --chain asset-hub-polkadot --base-path /tmp/node --name "Boot" --reserved-only --reserved-nodes "/dns/boot-polkadot-assethub.luckyfriday.io/tcp/443/wss/p2p/12D3KooWDR9M7CjV1xdjCRbRwkFn1E7sjMaL4oYxGyDWxuLrFc2J" --no-hardware-benchmarks

```

Bridgehub-Polkadot:

```
polkadot-parachain --chain bridge-hub-polkadot --base-path /tmp/node --name "Boot" --reserved-only --reserved-nodes "/dns/boot-polkadot-bridgehub.luckyfriday.io/tcp/443/wss/p2p/12D3KooWKf3mBXHjLbwtPqv1BdbQuwbFNcQQYxASS7iQ25264AXH" --no-hardware-benchmarks

```
Collectives-Polkadot

```
polkadot-parachain --chain collectives-polkadot --base-path /tmp/node --name "Boot" --reserved-only --reserved-nodes "/dns/boot-polkadot-collectives.luckyfriday.io/tcp/443/wss/p2p/12D3KooWCzifnPooTt4kvTnXT7FTKTymVL7xn7DURQLsS2AKpf6w" --no-hardware-benchmarks

```
Kusama:

```
polkadot --chain kusama --base-path /tmp/node --name "Boot" --reserved-only --reserved-nodes "/dns/boot-kusama.luckyfriday.io/tcp/443/wss/p2p/12D3KooWS1Lu6DmK8YHSvkErpxpcXmk14vG6y4KVEFEkd9g62PP8" --no-hardware-benchmarks

```
Assethub-Kusama:

```
polkadot-parachain --chain asset-hub-kusama --base-path /tmp/node --name "Boot" --reserved-only --reserved-nodes "/dns/boot-kusama-assethub.luckyfriday.io/tcp/443/wss/p2p/12D3KooWSwaeFs6FNgpgh54fdoxSDAA4nJNaPE3PAcse2GRrG7b3" --no-hardware-benchmarks
```

Bridgehub-Kusama:

```
polkadot-parachain --chain bridge-hub-kusama --base-path /tmp/node --name "Boot" --reserved-only --reserved-nodes "/dns/boot-kusama-bridgehub.luckyfriday.io/tcp/443/wss/p2p/12D3KooWQybw6AFmAvrFfwUQnNxUpS12RovapD6oorh2mAJr4xyd" --no-hardware-benchmarks
```

Co-authored-by: Bastian Köcher <[email protected]>

Based on issue
[#2512](https://github.com/paritytech/polkadot-sdk/issues/2512), it
seems that some ecosystem teams are using these networks to set up their
staging environments and test certain use cases, some of them involving
sending XCMs from the relay with origins not allowed in the current
configuration.

This change reverts the configuration of `SendXcmOrigin`.

---------

Co-authored-by: Adrian Catangiu <[email protected]>

Small refactoring to reduce the algorithmic complexity of the initial
message distribution in approval voting after a sync from O(n_candidates
^ 2) to O(n_candidates).

Changes needed to implement the runtime part of elastic scaling:
https://github.com/paritytech/polkadot-sdk/issues/3131,
https://github.com/paritytech/polkadot-sdk/issues/3132,
https://github.com/paritytech/polkadot-sdk/issues/3202

Also fixes https://github.com/paritytech/polkadot-sdk/issues/3675

TODOs:

- [x] storage migration
- [x] optimise process_candidates from O(N^2)
- [x] drop backable candidates which form cycles
- [x] fix unit tests
- [x] add more unit tests
- [x] check the runtime APIs which use the pending availability storage.
We need to expose all of them, see
https://github.com/paritytech/polkadot-sdk/issues/3576
- [x] optimise the candidate selection. we're currently picking randomly
until we satisfy the weight limit. we need to be smart about not
breaking candidate chains while being fair to all paras -
https://github.com/paritytech/polkadot-sdk/pull/3573

Relies on the changes made in
https://github.com/paritytech/polkadot-sdk/pull/3233 in terms of the
inclusion policy and the candidate ordering

---------

Signed-off-by: alindima <[email protected]>
Co-authored-by: command-bot <>
Co-authored-by: eskimor <[email protected]>

This PR backports:
- node version bump
- `spec_vesion` bump
- reordering of the `prdocs` to the appropriate folder
from the `1.9.0` release branch

Step in https://github.com/paritytech/polkadot-sdk/issues/3688

We witnessed really poor performance on Rococo, where we ended up with
50 on-demand cores. This was due to the fact that for each core the full
queue was processed. With this change full queue processing will happen
way less often (most of the time complexity is O(1) or O(log(n))) and if
it happens then only for one core (in expectation).

Also spot price is now updated before each order to ensure economic back
pressure.


TODO:

- [x] Implement
- [x] Basic tests
- [x] Add more tests (see todos)
- [x] Run benchmark to confirm better performance, first results suggest
> 100x faster.
- [x] Write migrations
- [x] Bump scale-info version and remove patch in Cargo.toml
- [x] Write PR docs: on-demand performance improved, more on-demand
cores are now non problematic anymore. If need by also the max queue
size can be increased again. (Maybe not to 10k)

Optional: Performance can be improved even more, if we called
`pop_assignment_for_core()`, before calling `report_processed` (Avoid
needless affinity drops). The effect gets smaller the larger the claim
queue and I would only go for it, if it does not add complexity to the
scheduler.

---------

Co-authored-by: eskimor <[email protected]>
Co-authored-by: antonva <[email protected]>
Co-authored-by: command-bot <>
Co-authored-by: Anton Vilhelm Ásgeirsson <[email protected]>
Co-authored-by: ordian <[email protected]>

The PR adds two things:
1. Runtime API exposing the whole claim queue
2. Consumes the API in `collation-generation` to fetch the next
scheduled `ParaEntry` for an occupied core.

Related to https://github.com/paritytech/polkadot-sdk/issues/1797

Introduces `CryptoBytes` type defined as:

```rust
pub struct CryptoBytes<const N: usize, Tag = ()>(pub [u8; N], PhantomData<fn() -> Tag>);
```

The type implements a bunch of methods and traits which are typically
expected from a byte array newtype
(NOTE: some of the methods and trait implementations IMO are a bit
redundant, but I decided to maintain them all to not change too much
stuff in this PR)

It also introduces two (generic) typical consumers of `CryptoBytes`:
`PublicBytes` and `SignatureBytes`.

```rust
pub struct PublicTag;
pub PublicBytes<const N: usize, CryptoTag> = CryptoBytes<N, (PublicTag, CryptoTag)>;

pub struct SignatureTag;
pub SignatureBytes<const N: usize, CryptoTag> = CryptoBytes<N, (SignatureTag, CryptoTag)>;
```

Both of them use a tag to differentiate the two types at a higher level.
Downstream specializations will further specialize using a dedicated
crypto tag. For example in ECDSA:


```rust
pub struct EcdsaTag;

pub type Public = PublicBytes<PUBLIC_KEY_SERIALIZED_SIZE, EcdsaTag>;
pub type Signature = PublicBytes<PUBLIC_KEY_SERIALIZED_SIZE, EcdsaTag>;
```

Overall we have a cleaner and most importantly **consistent** code for
all the types involved

All these details are opaque to the end user which can use `Public` and
`Signature` for the cryptos as before

On top of #3302.

We want the validators to upgrade first before we add changes to the
collation side to send the new variants, which is why this part is
extracted into a separate PR.

The detection of when to send the parent head is based on the core
assignments at the relay parent of the candidate. We probably want to
make it more flexible in the future, but for now, it will work for a
simple use case when a para always has multiple cores assigned to it.

---------

Signed-off-by: Matteo Muraca <[email protected]>
Signed-off-by: dependabot[bot] <[email protected]>
Co-authored-by: Matteo Muraca <[email protected]>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>
Co-authored-by: Juan Ignacio Rios <[email protected]>
Co-authored-by: Branislav Kontur <[email protected]>
Co-authored-by: Bastian Köcher <[email protected]>