We already have primitive/consensus and client/consensus folders to keep together consensus related code.

Currently these folders contains code for protocols related to block authoring such as BABE, AURA, PoW and some shared utility code.

I propose to add to these folders everything related to consensus (thus also finality) such as grandpa and beefy crates.

Even though this is not paramount, I can't see any good reason to have these crates floating with the rest of the code.
In general I think is a good practice to logically organize the code.

If there isn't any drawback I can easily take on this trivial chore.