feat(data/ulift): add `monad ulift` and `monad plift` (#3588)
feat(data/ulift): add `monad ulift` and `monad plift` (#3588)

We add `functor`/`applicative`/`monad` instances for `ulift` and `plift`.




leanprover-community/mathlib,leanprover-community/mathlib