Draft: merge rnHsTyPat and rnHsTyKi (#11101)

2afbddb0 introduced new function rnHsTyPat that copies code from rnHsTyKi

There was discussion about that having both rnHsTyPat and rnHsTyKi isn't good, and we want to merge them !10725 (comment 508148)

This is a draft of such merging, that also fixes #11101 and with this refactoring there may be a way to fix #13512

There are a bunch of problems with this patch

• a lot of outdated notes
• failing tests that I don't know how to solve: T14038, T13910, T13877
• broken spans in error messages
• I'm not sure about RnTypeM monad design

IMO, I decided to do too much in one pass, perhaps I need to think about how to make core changes of the patch (introducing RnTypeM) without changing anything else and then submit patches that use new infrastructure.

CC @simonpj