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

transaction-status/src/lib.rs

@@ -446,6 +446,19 @@ impl From<EncodedConfirmedBlock> for UiConfirmedBlock {
     }
 }
 
+impl From<UiConfirmedBlock> for EncodedConfirmedBlock {
+    fn from(block: UiConfirmedBlock) -> Self {
+        Self {
+            previous_blockhash: block.previous_blockhash,
+            blockhash: block.blockhash,
+            parent_slot: block.parent_slot,
+            transactions: block.transactions.unwrap_or_default(),
+            rewards: block.rewards.unwrap_or_default(),
+            block_time: block.block_time,
+        }
+    }
+}
+
 #[derive(Debug, Clone, Copy, PartialEq, Serialize, Deserialize)]
 #[serde(rename_all = "camelCase")]
 pub enum TransactionDetails {