Cumulus test service cleanup (paritytech#2887)

closes paritytech#2567 

Followup for paritytech#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`

substrate/bin/node/cli/benches/transaction_pool.rs

@@ -55,7 +55,7 @@ fn new_node(tokio_handle: Handle) -> node_cli::service::NewFullBase {
 		impl_name: "BenchmarkImpl".into(),
 		impl_version: "1.0".into(),
 		role: Role::Authority,
-		tokio_handle,
+		tokio_handle: tokio_handle.clone(),
 		transaction_pool: TransactionPoolOptions {
 			ready: PoolLimit { count: 100_000, total_bytes: 100 * 1024 * 1024 },
 			future: PoolLimit { count: 100_000, total_bytes: 100 * 1024 * 1024 },
@@ -97,7 +97,9 @@ fn new_node(tokio_handle: Handle) -> node_cli::service::NewFullBase {
 		wasm_runtime_overrides: None,
 	};
 
-	node_cli::service::new_full_base(config, None, false, |_, _| ()).expect("Creates node")
+	tokio_handle.block_on(async move {
+		node_cli::service::new_full_base(config, None, false, |_, _| ()).expect("Creates node")
+	})
 }
 
 fn create_accounts(num: usize) -> Vec<sr25519::Pair> {