Implement `Narwhal & Bullshark` consensus as substrate client consensus

[AbdelStark]

Description

We need to do some research work and implement Narwhal & Bullshark consensus as a substrate consensus client and perform some benchmarks.

Resources

• Narwhal and Tusk: A DAG-based Mempool and Efficient BFT Consensus
• Bullshark: DAG BFT Protocols Made Practical
• Narwal Rust implementation in Sui

[tdelabro]

I will work on this!