* introduce relayers pallet

* add MessageDeliveryAndDispatchPaymentAdapter

* plug in pallet into test runtimes

* tests prototype

* tests for the relayers pallet

* tests for payment adapter

* mint_reward_payment_procedure_actually_mints_tokens

* benchmarks

* remove irrelevant todo

* remove redundant clone

* decrease parameters range in grandpa benchmarks

* fix messages benchmarks

* update all weights

* dealing with failed test (WiP)

* Revert "dealing with failed test (WiP)"

This reverts commit 0379d24b.

* proper tests fix

* move brnchmarks from Rialto to Millau

* fix limits test

* token swap benchmarks

* spellcheck

* updated weight formula for submit_finality_proof

* remove common prefix traces

* update docs

* single benchmark

* Re-generate weights.

* Update delivery transaction limits

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

* Insert headers in benchmarks.

* Fix benchmarks.

* Lower number of headers.

* Avoid hardcoding numbers.

* Update weights.

* cargo fmt --all

* Remove todo.

* Fix test.

* Address review comments.

* Fix borrowed value.

* New weights.

* Fix test.

* cargo fmt --all

* Use more accurate weight calculation in declared weight

* Remove session length and validator set size config constants

* Remove config params from mock

* Allow specifying total number of votes-ancestries per justification

* Change limits used during benchmarking

* Regenerate weights

* Use simplified weight annotation

* Remove comment

* Address leftover TODO

* Prevent possible divide by zero errors

* Use correct argument order in weight declaration

* Add benchmarking skeleton

* Allow runtime to indicate concrete header type for benches

* Set up skeleton for benchmark tests

* Play around with mutating bench header

* Create a working test for benchmarking

* Add benches related to enacting authority set changes

* Add bench for checking effect of prec-commits/vote ancestries

* Use new `no_std` test utils in benchmarks

* Support pallet instances in benchmarking

* Use correct benchmarking instance macro

* Add instance to runtime benchmark helper impl

* Start using new justification creation API

* Allow mock header's number to be specified

* Set up benches with correct fork/depth parameters

* Use new pallet name during runtime bench setup

* Use correct `set_id` in tests

* Limit number of forks as workaround to get tests passing

* Use number of authorities which matches number of forks

* Make sure test post-conditions are checked properly

* Only read `Current...