* Decouple `relays/client-substrate` from `headers_relay`
* Remove `blocks_in_state` from `SyncLoopMetrics`
    This metric was only relevant for PoA <> Substrate bridge.
* Move `sync_loop_metrics.rs` to `relays/finality`
* Remove unused `SyncLoopMetrics::update()`
* Hook up SyncLoopMetrics to finality_loop
* Delete now unused `relays/headers`

Signed-off-by: acatangiu <[email protected]>

* Unify error enums in substrate and ethereum clients with `thiserror`

Related to https://github.com/paritytech/parity-bridges-common/issues/857

* Add license pre-amble

* rustfmt

* Fix spelling

* shared conversion rate metric value

* clippy

* Stop passing raw encoded justifications to pallet API

By having the API accept a struct-ified justification we are able to
better utilize the justifications fields for weight calculations.

* Update relayer code to use decoded justifications

* Add justification to `expect()` statement

* Fix some imports

* Make justification wrapper contain decoded justification

* Rename some fields

* Get rid of warnings

* Appease Clippy

* Only decode justification once at init time

* Remove unnecessary method

* Remove justification wrapper

This became kinda unnecessary since we could implement the FinalityProof
trait on GrandpaJustification directly.

* Remove chains.

* Move relay clients.

* Flatten generic.

* Fix fmt.

* Nest some crates.

* Alter command execution to make it easier to add new bridges.

* Rename sub-dirs.

* cargo fmt --all

* Address clippy.

* Update relays/substrate/src/rialto_millau/cli.rs

Co-authored-by: Hernando Castano <[email protected]>

Co-authored-by: Hernando Castano <[email protected]>

* finality proofs relay

* SyncHeader::is_mandatory

* empty ancestry proof

* logs

* fixed submit condition

* fixed wrong split index

* tick comment

* recent_finality_proofs

* basic finality loop tests

* removed obsolete files

* rename files in substrate relay

* fmt

* clippy

* fixed TODOs

* clippy

* stop syncing if target node is out of sync

* more clippy

* more clippy

* Update relays/finality-relay/src/finality_loop.rs

Co-authored-by: Hernando Castano <[email protected]>

* Update relays/finality-relay/src/finality_loop.rs

Co-authored-by: Hernando Castano <[email protected]>

* Update relays/finality-relay/src/finality_loop.rs

Co-authored-by: Hernando Castano <[email protected]>

* docs

* moved doc

* typo

* Update relays/finality-relay/src/finality_loop_tests.rs

Co-authored-by: Hernando Castano <[email protected]>

* Update relays/finality-relay/src/finality_loop_tests.rs

Co-authored-by: Hernando Castano <[email protected]>

* header_and_finality_proof_by_number -> header_and_finality_proof

* VecDeque isn't required (because of make_contiguous)

* fixed wrong expect

* Update relays/finality-relay/src/finality_loop.rs

Co-authored-by: Hernando Castano <[email protected]>

* Update relays/substrate/src/rialto_headers_to_millau.rs

Co-authored-by: Hernando Castano <[email protected]>

* Update relays/substrate/src/rialto_headers_to_millau.rs

Co-authored-by: Hernando Castano <[email protected]>

* RialtoSyncHeader

* Update relays/finality-relay/src/finality_loop.rs

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

* Update relays/finality-relay/src/finality_loop.rs

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

* removed wrong comment

* Update relays/finality-relay/src/finality_loop.rs

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

* fix used runtime methods names

* fix for new jsonrpsee

* fix comment

* initialize finality verifier pallet

* fmt

Co-authored-by: Hernando Castano <[email protected]>
Co-authored-by: Tomasz Drwięga <[email protected]>

* extracted relay crates

* moved metrics to utils

* exchange-relay compilation

* fix compilation of headers-relay

* fixed messages-relay compilation

* fixed ethereum-poa-relay compilation

* cargo lock

* cargo fmt --all

* clippy

* cargo fmt --all

* fix tests compilation

* clippy

* eof

* module level docs

* removed obsolete comment

* #![warn(missing_docs)]

* .0 -> Deref

* post-merge fix

* cargo fmt

* Update relays/headers-relay/src/headers.rs

Co-authored-by: Hernando Castano <[email protected]>

* Update relays/headers-relay/src/headers.rs

Co-authored-by: Hernando Castano <[email protected]>

* Update relays/headers-relay/src/lib.rs

Co-authored-by: Hernando Castano <[email protected]>

Co-authored-by: Hernando Castano <[email protected]>