L2: Implement a better separation between dev and prod functionality for the OnChainProposer.

[fkrause98]

Description

Currently, to distinguish when to use (or not) a certain verifier, we simply check with if statements
certain variables, this is dangerously error prone. I think the correct would be to have:

• 2 contracts.

• They should have almost the same code, but be different enough to be used in dev and prod.

• We should also have checks for which contract we're using, something like the keccack
  of each contract to check we're deploying exactly the one we want.

• Keep a CI check that guarantees the dev and prod contracts stay mostly the same, besides the few needed
  changes for each environment.