* Implement public helpers for querying header info
* Update `best_header` when importing headers
* Add BestHeader to GenesisConfig
* Define extra types for Millau primitives
* Start implementing runtime APIs in Millau runtime
* Add helper for getting headers which require a justification
* Add runtime API for getting headers requiring a justification
* Reword `expect()` proof for valid authority sets
* Fix typo
* Clean up Hasher comment
* Add the Call Dispatch Pallet back to the Millau runtime
* Use types from Rialto in bridge pallet config
* Use the Rialto runtime APIS in the Millau runtime
* Include Millau bridge instance in Rialto runtime
* Add missing doc comment
* Use one storage function for setting and clearing `RequiresJustification`
* Remove TODO comments
* Split the Rialto Node into a standalone crate
* Split the Millau Node into a standalone crate
* Remove `bridge-node` crate
* Add benchmarking feature to nodes
* Check that benchmarks compile in CI
* Remove nodes from CI matrix
* Update Rialto node to Substrate 2.0
* Get Millau node compiling with Substrate 2.0
* Remove extra license text
* Remove comments in TOML files
* Move nodes and runtimes into Rialto and Millau folders
* Fix dependency paths
* Remove unused script
* Add issue to benchmarking TODO
* Fix benchmark manifest paths