Pass owner to navigator when it can be inferred from the target

[Bawnorton]

Following on from #2616

As it turns out simply transforming the result of getCustomOwner was almost enough by itself, I just did it wrong in testing before 😅, however, when it comes to navigating to the target there were a couple of issues. Notably injection points would rely on the untransformed class passed from the AtResolver (providing the selector with enough context to transform that per #2616 would be a bit of a pain).

MinecraftDev/src/main/kotlin/platform/mixin/handlers/injectionPoint/AtResolver.kt

Line 230 in 66f57a6

val targetPsiClass = getTargetClass(target)

This results in the injection points looking for the target in the wrong class, so instead, where possible we trust the qualifier of the target (for INVOKE/INVOKE_ASSIGN/FIELD) to find the element, which ultimately seems to have done the trick for most injection points.

Notably HEAD would wind up getting stuck in the target's injector annotation itself, resulting in a target resolution failure, so I opted to skip annotation visiting on that injection point navigator as there isn't any reason HEAD should point there anyway.

The injection points CONSTANT/NEW/CTOR_HEAD worked out the box which was convenient, however MIXINEXTRAS:EXPRESSION has a an issue that any definitions that reference a member "belonging" to the mixin will fail to navigate to from the gutter icon as eventually the qualifier will be queried on said member by ME's matching algorithm which will resolve as the mixin rather than the qualifier in the definition. If I were to make the same change to ME's matching it'd be to trust the definition qualifier when looking for the member rather than the AST's qualifier, however, I don't know the best way to implement that as there's a lot going on there.

This fails:

This succeeds:

Also fixes source file lookup when referencing same-project / sibling-project class, as sometimes the file is already decompiled when you get it via stubClass.containingFile