Remove type aliases for U2 etc. types

[cmeeren]

I find this signature confusing:

I have no idea what AnchorElProp is. So I write AnchorElProp and get this:

Which is absolutely no help at all. So I actually have to go to the online documentation and look it up.

It would be much easier if the type abbreviation was removed, because then it would say U2<EventTarget, unit‑>EventTarget> instead of AnchorElProp right in the IDE, and I would be spared all this unnecessary looking up 😉

I see this goes for some other props as well.