fix(fromEvent): match targets properly; fix result selector type

[cartant]

Description:

This PR fixes some problems with fromEvent:

• The interfaces used to match targets need to use methods instead of props. Otherwise, extends behaves in an unintended manner and the types won't match.
• There is a signature that takes only the target and the event name, so the optional qualifiers on the other signatures are redundant.
• If the resultSelector returns T, the target's type should not be FromEventTarget<T>.

The typing of fromEvent could be improved, but I think the first step is to fix these problems. The next would be to replace the FromEventTarget type with separate signatures.

Related issue (if exists): Nope

[benlesh]

The interfaces used to match targets need to use methods instead of props. Otherwise, extends behaves in an unintended manner and the types won't match.

WTF. 🙄 lol

[benlesh]

This seems to make sense. We're loosing up the type here, because really it's the T that matters. However, part of me feels like we should undeprecate this signature (as discussed in #5824), and in that case, we should try to get the types correct that are being passed to the result selector. I suppose we can do that in another pass though.

[cartant]

Yeah. That's something that can be done after it's split into separate signatures. ATM, FromEventTarget makes the function look simpler than it really is and the T is really only applicable to some of the signatures.