We don't use any explicit `#[lang = ...]` items anymore (`panic_fmt`
is replaced with now-stable `#[panic_implementation]`, OOM is handled
via `alloc_error_handler` directly etc.), so I thought it'd be good to
remove it for clarity to limit used nightly features.

* Extend `Proposer` to optionally generate a proof of the proposal

* Something

* Refactor sr-api to not depend on client anymore

* Fix benches

* Apply suggestions from code review

Co-Authored-By: Tomasz Drwięga <[email protected]>

* Apply suggestions from code review

* Introduce new `into_storage_changes` function

* Switch to runtime api for `execute_block` and don't require `H256`
anywhere in the code

* Put the `StorageChanges` into the `Proposal`

* Move the runtime api error to its own trait

* Adds `StorageTransactionCache` to the runtime api

This requires that we add `type NodeBlock = ` to the
`impl_runtime_apis!` macro to work around some bugs in rustc :(

* Remove `type NodeBlock` and switch to a "better" hack

* Start using the transaction cache from the runtime api

* Make it compile

* Move `InMemory` to its own file

* Make all tests work again

* Return block, storage_changes and proof from Blockbuilder::bake()

* Make sure that we use/set `storage_changes` when possible

* Add test

* Fix deadlock

* Remove accidentally added folders

* Introduce `RecordProof` as argument type to be more explicit

* Update client/src/client.rs

Co-Authored-By: Tomasz Drwięga <[email protected]>

* Update primitives/state-machine/src/ext.rs

Co-Authored-By: Tomasz Drwięga <[email protected]>

* Integrates review feedback

* Remove `unsafe` usage

* Update client/block-builder/src/lib.rs

Co-Authored-By: Benjamin Kampmann <[email protected]>

* Update client/src/call_executor.rs

* Bump versions

Co-authored-by: Tomasz Drwięga <[email protected]>
Co-authored-by: Benjamin Kampmann <[email protected]>

* clean up cargo.toml syntax

* bumping versions to 2.0

* bump networking to 0.8

* move consensus down to 0.8

* bump consensus pallets to 0.8.0, too

* Upping babe and aura pallets

* add remaining, missing version definitions

* missed some

* Rename: Phase 1.

* Unify codec.

* Fixing: Phase 2

* Fixing: Phase 3.

* Fixing: Phase 4.

* Fixing: Phase 5.

* Fixing: Phase 6.

* Fixing: Phase 7.

* Fixing: Phase 8. Tests

* Fixing: Phase 9. Tests!!!

* Fixing: Phase 10. Moar tests!

* Finally done!

* More fixes.

* Rename primitives:: to sp_core::

* Apply renames in finality-grandpa.

* Fix benches.

* Fix benches 2.

* Revert node-template.

* Fix frame-system in our modules.

* In progress, runtime io must switch to future proof root +
child_specific (unique id) + u32 type.

* Switch interface, sr-io seems ok, rpc could use similar interface to
sr-io, genesis json broken if there is child trie in existing encoding
genesis.

* test from previous implementation.

* fix proving test.

* Restore Keyspacedb from other branch, only apply to child trie.

* Removing unneeded child_info from child root (child info are stored
if things changed, otherwhise the root does not change).

* Switch rpc to use same format as ext: more future proof.

* use root from child info for trie backend essence.

* Breaking long lines.

* Update doc and clean pr a bit.

* fix error type

* Restore removed doc on merge and update sr-io doc.

* Switch child storage api to use directly unique id, if managed id
where to be put in place, the api will change at this time.

* Clean deprecated host interface from child.

* Removing assertion on child info (can fail depending on root
memoization).

* merging child info in the overlay when possible.

* child iteration by prefix using child_info.

* Using ChainInfo in frame support. ChainInfo gets redesign to avoid
buffers allocation on every calls.

* Add length of root to the data of child info.

* comments

* Encode compact.

* Remove child info with root.

* Fix try_update condition.

* Comment Ext child root caching.

* Replace tuples by struct with field

* remove StorageTuple alias.

* Fix doc tests, and remove StorageOverlay and ChildStorageOverlay
aliases.

* primitives/sr-io -> primitives/io

* fix

* rename

* runtime-io -> sp-io

* git mv

* fix ci

* remove package name

* fix

* fix

* try minimizing diff

* try minimizing diff again

* try minimizing diff again