* Deprecate commitment variants
* Add new CommitmentConfig builders
* Add helpers to avoid allowing deprecated variants
* Remove deprecated transaction-status code
* Include new commitment variants in runtime commitment; allow deprecated as long as old variants persist
* Remove deprecated banks code
* Remove deprecated variants in core; allow deprecated in rpc/rpc-subscriptions for now
* Heavier hand with rpc/rpc-subscription commitment
* Remove deprecated variants from local-cluster
* Remove deprecated variants from various tools
* Remove deprecated variants from validator
* Update docs
* Remove deprecated client code
* Add new variants to cli; remove deprecated variants as possible
* Don't send new commitment variants to old clusters
* Retain deprecated method in test_validator_saves_tower
* Fix clippy matches! suggestion for BPF solana-sdk legacy compile test
* Refactor node version check to handle commitment variants and transaction encoding
* Hide deprecated variants from cli help
* Add cli App comments
* Add service to track the most recent optimistically confirmed bank
* Plumb service into ClusterInfoVoteListener and ReplayStage
* Clean up test
* Use OptimisticallyConfirmedBank in RPC
* Remove superfluous notifications from RpcSubscriptions
* Use crossbeam to avoid mpsc recv_timeout panic
* Review comments
* Remove superfluous last_checked_slots, but pass in OptimisticallyConfirmedBank for complete correctness
* Remove Blockstore member variable from BlockCommitmentCache
* Hoist is_confirmed_rooted() to its only caller
BlockCommitmentCache no longer depends on Blockstore
* Move BlockCommitmentCache to solana_runtime