Ignore hlints + warnings in generated modules

[brandon-leapyear]

All generated modules (API + enums) should include

{-# OPTIONS_GHC -w #-}
{-# ANN module "HLint: ignore" #-}

So that we don't get any GHC warnings (that could turn into compile-time errors if someone turns on -Werror) and HLint doesn't check this file (ref)