Cumulus test service cleanup (#2887)

closes #2567 

Followup for https://github.com/paritytech/polkadot-sdk/pull/2331

This PR contains multiple internal cleanups:

1. This gets rid of the functionality in `generate_genesis_block` which
was only used in one benchmark
2. Fixed `transaction_pool` and `transaction_throughput` benchmarks
failing since they require a tokio runtime now.
3. Removed `parachain_id` CLI option from the test parachain
4. Removed `expect` call from `RuntimeResolver`

cumulus/test/service/src/cli.rs

@@ -38,9 +38,6 @@ pub struct TestCollatorCli {
 	#[command(flatten)]
 	pub run: cumulus_client_cli::RunCmd,
 
-	#[arg(default_value_t = 2000u32)]
-	pub parachain_id: u32,
-
 	/// Relay chain arguments
 	#[arg(raw = true)]
 	pub relaychain_args: Vec<String>,
@@ -256,9 +253,8 @@ impl SubstrateCli for TestCollatorCli {
 
 	fn load_spec(&self, id: &str) -> std::result::Result<Box<dyn sc_service::ChainSpec>, String> {
 		Ok(match id {
-			"" => Box::new(cumulus_test_service::get_chain_spec(Some(ParaId::from(
-				self.parachain_id,
-			)))) as Box<_>,
+			"" =>
+				Box::new(cumulus_test_service::get_chain_spec(Some(ParaId::from(2000)))) as Box<_>,
 			path => {
 				let chain_spec =
 					cumulus_test_service::chain_spec::ChainSpec::from_json_file(path.into())?;