BlockId removal: refactor: StorageProvider (#12510)

* BlockId removal: refactor: StorageProvider

It changes the arguments of `Backend::StorageProvider` trait from:
block: `BlockId<Block>` to: hash: `&Block::Hash`

This PR is part of BlockId::Number refactoring analysis (paritytech/substrate#11292)

* Apply suggestions from code review

Co-authored-by: Bastian Köcher <[email protected]>

* Update client/api/src/backend.rs

Co-authored-by: Dmitrii Markin <[email protected]>

* GrandpaBlockImport::current_set_id reworked

* ExportStateCmd reworked

* trigger CI job

* trigger CI job

Co-authored-by: Bastian Köcher <[email protected]>
Co-authored-by: Dmitrii Markin <[email protected]>