No RPC API to check that a transaction wasn't processed by a particular slot

[jstarry]

Problem

To properly determine that a transaction has expired, it's necessary to check with an RPC node that the transaction hasn't been processed before a particular slot at a particular commitment level. This need arises from the fact that RPC nodes could be lagging far behind the block producer and may not have confirmed the last block that a transaction could have been processed in yet.

Unfortunately the getSignatureStatus and getTransaction API's aren't suitable for this type of query because getSignatureStatus can't be called with a commitment level and getTransaction doesn't return the context slot in which the request was evaluated.

Originally posted by @jstarry in #25839 (comment)

Proposed Solution

Introduce getTransactionStatus API which accepts a commitment parameter and returns a context wrapped response. This API will indicate whether a transaction was included in a block or not.