GHC-83865 is (too?) generic of an error code

Motivation

GHC-83865, "TypeEqMismatch", seems to cover many errors that could perhaps be given more specific, individual codes.

It covers situations where:

1. A type is expected, but a kind is given ("Expected a type, but ‘Maybe’ has kind ‘* -> *’")
2. Type a is expected, but type b is given ("Couldn't match expected type ‘Int’ with actual type ‘Char’")
3. Levity mismatch ("Couldn't match a lifted type with an unlifted type")
4. Kind a is expected, but kind b is given ("Expected kind ‘* -> k3’, but ‘Type’ has kind ‘*’")
5. SimplifiedSubsumption breaks code ("Couldn't match type ‘()’ with ‘forall t. t’")
6. A special case of (2) that adds the message, "The function ‘t2’ is applied to one value argument, but its type ‘Int’ has none"

I can recognize how these are all examples of "the same thing", but in practice they cover a lot of ground and would make an entry in https://errors.haskell.org pretty unwieldy.

Proposal

I don't have a concrete proposal, as someone unfamiliar with the specifics of errors. I am hoping someone can help choose between these outcomes:

1. Bite the bullet and write a dissertation for the errors.haskell.org entry
2. Create new codes to represent the most pertinent distinct situations
3. Somehow improve the message when SimplifiedSubsumption is suspected