Request: split off `Untyped decorator makes function "..." untyped` from `[misc]`

[Avasam]

Feature

When getting the error Untyped decorator makes function "..." untyped, I'd like for it to be a different error code than the catch-all misc

Pitch

In https://github.com/microsoft/python-type-stubs/, most of the hundreds of misc errors are due to untyped decorators. Reviewing whether each decorator should affect the signature (meaning it could just be removed in a stub), or typing them (typing decorators isn't easy or fast) would take a ton of effort. With the hundreds of violations, the entire misc category is ignored. This is unfortunate as there's other very valuable errors to be found in that category.

I could also see that code being disabled when mypy is used alongside another checker/language server that supports inferred return types and a decorator returning a callable class is used.

In partially typed projects, maintainers may opt out of this error if they find typing decorators to be too complex.

[JelleZijlstra]

Seems like a good idea, in general it's good to get things out of misc if they're at all common.