Fix TypeData issues (fixes #22315 and #22332)

There were two bugs here:

1. Treating type-level constructors as PromotedDataCon doesn't always
   work, in particular because constructors promoted via DataKinds are
   called both T and 'T. (Tests T22332a, T22332b, T22315a, T22315b)
   Fix: guard these cases with isDataKindsPromotedDataCon.

2. Type-level constructors were sent to the code generator, producing
   things like constructor wrappers. (Tests T22332a, T22332b)
   Fix: test for them in isDataTyCon.

Other changes:

* changed the marking of "type data" DataCon's as suggested by SPJ.

* added a test TDGADT for a type-level GADT.

* comment tweaks

* change tcIfaceTyCon to ignore IfaceTyConInfo, so that IfaceTyConInfo
  is used only for pretty printing, not for typechecking. (SPJ)