* Add runtime methods to simply get status and slot
* Add helper function to get slot confirmation_count from BlockCommitmentCache
* Return cluster confirmations in getSignatureStatus
* Remove use of invalid get_signature_confirmation_status
* Remove unused methods
* Update pubsub to use cluster confirmations
* Fix test_check_signature_subscribe failure
* Refactor confirmations to read commitment cache only once
* Review comments
* Use bank, root from BlockCommitmentCache
* Update docs
* Add metric for block-commitment aggregations
Co-authored-by: Justin Starry <justin@solana.com>