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

Another simple refactory to prune some duplicate code

Follow up of: https://github.com/paritytech/polkadot-sdk/pull/3684

Devs seem to not realize that this should be filled out manually. The
default is also often wrong.

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`.

cc https://github.com/paritytech/ci_cd/issues/943

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

---------

Co-authored-by: eskimor <eskimor@no-such-url.com>
Co-authored-by: Adrian Catangiu <adrian@parity.io>

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 <adrian@parity.io>

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.

Bridging fees are calculated using a static ETH/DOT exchange rate that
can deviate significantly from the real-world exchange rate. We
therefore need to add a safety margin to the fee so that users almost
aways cover the cost of relaying.

# FAQ

> Why introduce a `multiplier` parameter instead of configuring an
exchange rate which already has a safety factor applied?

When converting from ETH to DOT, we need to _divide_ the multiplier by
the exchange rate, and to convert from DOT to ETH we need to _multiply_
the multiplier by the exchange rate.

> Other input parameters to the fee calculation can also deviate from
real-world values. These include substrate weights, gas prices, and so
on. Why does the multiplier introduced here not adjust those?

A single scalar multiplier won't be able to accommodate the different
volatilities efficiently. For example, gas prices are much more volatile
than exchange rates, and substrate weights hardly ever change.

So the pricing config relating to weights and gas prices should already
have some appropriate safety margin pre-applied.

# Detailed Changes:

* Added `multiplier` field to `PricingParameters`
* Outbound-queue fee is multiplied by `multiplier`
* This `multiplier` is synced to the Ethereum side
* Improved Runtime API for calculating outbound-queue fees. This API
makes it much easier to for configure parts of the system in preparation
for launch.
* Improve and clarify code documentation

Upstreamed from https://github.com/Snowfork/polkadot-sdk/pull/127

---------

Co-authored-by: Clara van Staden <claravanstaden64@gmail.com>
Co-authored-by: Adrian Catangiu <adrian@parity.io>

## Bug Explanation
Adds a check that prevents finalized headers with a gap larger than the
sync committee period being imported, which could cause execution
headers in the gap being unprovable. The current version of the Ethereum
client checks that there is a header at least every sync committee, but
it doesn't check that the headers are within a sync period of each
other. For example:

Header 100 (sync committee period 1)
Header 9000 (sync committee period 2)
(8900 blocks apart)

These headers are in adjacent sync committees, but more than the sync
committee period (8192 blocks) apart.

The reason we need a header every 8192 slots at least, is the header is
used to prove messages within the last 8192 blocks. If we import header
9000, and we receive a message to be verified at header 200, the
`block_roots` field of header 9000 won't contain the header in order to
do the ancestry check.

## Environment
While running in Rococo, this edge case was discovered after the relayer
was offline for a few days. It is unlikely, but not impossible, to
happen again and so it should be backported to polkadot-sdk 1.7.0 (so
that
[polkadot-fellows/runtimes](https://github.com/polkadot-fellows/runtimes)
can be updated with the fix).

Our Ethereum client has been operational on Rococo for the past few
months, and this been the only major issue discovered so far.

### Unrelated Change
An unrelated nit: Removes a left over file that should have been deleted
when the `parachain` directory was removed.

---------

Co-authored-by: claravanstaden <Cats 4 life!>

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 <git@kchr.de>

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 <adrian@parity.io>

Make taplo happy

There was a typo, so now, there's no more typo.

Co-authored-by: Liam Aharon <liam.aharon@hotmail.com>

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 <alin@parity.io>
Co-authored-by: command-bot <>
Co-authored-by: eskimor <eskimor@users.noreply.github.com>