Add hidden cli option to allow validator reports replayed transaction cost metrics (#22369)

* add hidden cli option to allow validator reports replayed transaction cost detail metrics

* Update validator/src/main.rs

Co-authored-by: Michael Vines <mvines@gmail.com>

* - rebase master, using unbounded instead of channel; dowgrade to datapoint_trace

* removed cli arg, prefer log at trace

Co-authored-by: Michael Vines <mvines@gmail.com>

runtime/src/lib.rs

@@ -57,6 +57,7 @@ pub mod stakes;
 pub mod status_cache;
 mod system_instruction_processor;
 pub mod transaction_batch;
+pub mod transaction_cost_metrics_sender;
 pub mod vote_account;
 pub mod vote_sender_types;
 pub mod waitable_condvar;