Generalise QuickCheck combinators for any stack of monad transformers

Our codebase (specifically on the `feature/utxo-hd` branch) includes a few generalised QuickCheck combinators that work for transformers of the Gen monad. If we would want to be more general, we could make the generators work for any stack of transformers (i.e., use something like a MonadGen class).

See https://github.com/input-output-hk/ouroboros-network/pull/3824#discussion_r915827405 for examples.