Rpc: enable getConfirmedBlock and getConfirmedTransaction to return confirmed (not yet finalized) data (#16142)

* Add Blockstore block and tx apis that allow unrooted responses

* Add TransactionStatusMessage, and send on bank freeze; also refactor TransactionStatusSender

* Track highest slot with tx-status writes complete

* Rename and unpub fn

* Add commitment to GetConfirmed input configs

* Support confirmed blocks in getConfirmedBlock

* Support confirmed txs in getConfirmedTransaction

* Update sigs-for-addr2 comment

* Enable confirmed block in cli

* Enable confirmed transaction in cli

* Review comments

* Rename blockstore method

sdk/src/commitment_config.rs

@@ -108,6 +108,10 @@ impl CommitmentConfig {
         )
     }
 
+    pub fn is_at_least_confirmed(&self) -> bool {
+        self.is_confirmed() || self.is_finalized()
+    }
+
     pub fn use_deprecated_commitment(commitment: CommitmentConfig) -> Self {
         match commitment.commitment {
             CommitmentLevel::Finalized => CommitmentConfig::max(),