Add block height to ConfirmedBlock structs (#17523)

* Add BlockHeight CF to blockstore

* Rename CacheBlockTimeService to be more general

* Cache block-height using service

* Fixup previous proto mishandling

* Add block_height to block structs

* Add block-height to solana block

* Fallback to BankForks if block time or block height are not yet written to Blockstore

* Add docs

* Review comments

cli-output/src/cli_output.rs

@@ -2126,6 +2126,9 @@ impl fmt::Display for CliBlock {
         if let Some(block_time) = self.encoded_confirmed_block.block_time {
             writeln!(f, "Block Time: {:?}", Local.timestamp(block_time, 0))?;
         }
+        if let Some(block_height) = self.encoded_confirmed_block.block_height {
+            writeln!(f, "Block Height: {:?}", block_height)?;
+        }
         if !self.encoded_confirmed_block.rewards.is_empty() {
             let mut rewards = self.encoded_confirmed_block.rewards.clone();
             rewards.sort_by(|a, b| a.pubkey.cmp(&b.pubkey));