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`