* Allow bridge pallet to return no finalized headers

* Update Runtime APIs to optionally return best finalized header

* Update relay to handle optional best finalized headers

* Fix Clippy lints

* Return a dummy header instead of an Option

* Remove Option from runtime Apis

* Remove support for handling optional finalized headers in relay

* limit messages in the batch by weight/count

* fixed components compilation

* reverted obsolete parts of #469

* implement generated_messages_weights

* actually use computed weight in message proof

* fmt and clippy

* fixed TODO

* clippy

* Update relays/messages-relay/src/message_race_loop.rs

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

* add issue reference

* add assert message

* grumbles

* fmt

* reexport weight from bp-message-lane

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

* Millau messages -> Rialto relay

* prepare for custom race strategy of delivery race

* custom strategy for delivery race

* update TODOs

* add reference to issue 457

* impl reconnect

* clippy

* fix check in test

* fmt

* removed obsolete TODO

* fixed another TODOs

* fmt

* use MAX_UNCONFIRMED_MESSAGES_AT_INBOUND_LANE const from primitives

* Update relays/messages-relay/src/message_lane_loop.rs

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

* added SubstrateMessagesProof typedef

* fix test

* removed comment

* additional_proof_required -> ProofParameters

* typo

* multiline literal

* clippy

* fix typo

* and_then -> await

* update_source_latest_confirmed_nonce

* Update relays/messages-relay/src/message_race_delivery.rs

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

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

* Rialto -> Millau headers relay

* removed more constraints

* removed file from other PR

* Update primitives/rialto/src/lib.rs

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

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

* substrate relay guards

* checked time condition

* ChainWithBalances

* removed obsolete comment

* Update relays/substrate-client/src/chain.rs

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

* trailing space

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

* maintain MillauHeadersToRialto sync by subscribing to Millau justifications

* more tracing in maintain

* Update relays/substrate/src/headers_maintain.rs

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

* Update relays/substrate/src/headers_maintain.rs

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

* -Please

* -TODO

* revert raise recursion limit

* updated comment

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

* working-millau-to-rialto-relay

* fix Millau state root

* properly fix synced+incomplete headers for sub2sub

* removed wrong TODO

* fmt + clippy

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

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

* moved SubstrateTransactionMaker definition

* removed M from phantomdata

* removed prune_synced_children

* methods names as consts

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

* extract ChainBase to bp-runtime

* post-merge fixes

* cargo fmt --all

* compilation fixes

* reexport BlockNumberOf, HashOf, HeaderOf

* substrate-relay: initial commit

* MillauHeaderApi and RialtoHeaderApi

* post-merge fixes + TODOs + compilation

* extracting sub clients

* fmt + lost docs

* revert enum BridgeInstance

* apply suggestions from review

* explicite debug impl

* remove unused imports from Millau

* fix typo

* fix instance + API name

* Update relays/ethereum/src/ethereum_sync_loop.rs

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

* separate crates for millau and rialto client

* cargo fmt

* fix

* fmt

* remove no_std support

* fix compilation again

* Update relays/substrate-client/Cargo.toml

* Update relay clients to Substrate 2.0

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