Backport two recent PRs from polkadot-staging branch (#2828)

* Add submit_finality_proof_ex call to the GRANDPA pallet (#2821)

* depreacte submit_finality_proof and introduce submit_finality_proof_ex instead

* propagate changes to the rest of runtime crates

* tests for new call

* suppress deprecation warning

* revert changes to benchmarks to avoid unnecessary compilation issues when integrating to other repos

* Pass finality proof verification context to the call builder (#2823)

* pass verification context to the build_submit_finality_proof_call

* current_set_id -> context