Transaction pool: Adds benchmark and improves performance (#9958)

* Yep

* Make it compile

* Make the benchmark work

* Some stuff

* Optimize transaction pool `BestIterator`

* Some docs

* Fix more warnings

* Fix compilation

* FMT

substrate/bin/node/cli/src/lib.rs

@@ -33,7 +33,7 @@
 pub mod chain_spec;
 
 #[macro_use]
-mod service;
+pub mod service;
 #[cfg(feature = "cli")]
 mod cli;
 #[cfg(feature = "cli")]