Automatically detect property/attribute for HTMLDOMPropertyConfig

Proper implementation of #1512

It does not get rid of `MUST_USE_PROPERTY` (see #2140) and `MUST_USE_ATTRIBUTE` because I'm not 100% sure if we might want to use it or not, I assume there's no need for it.

I also removed a test that I'm not sure what to do about. It relied on really hacky behavior and I don't really see a simple way of keeping it alive (not really familiar with testing), but please shout if you think otherwise.