- add default `resolve()` implementation;
- don't use `PsiImplUtil`;
- remove implementations from inheritors.

Another side effect of this is that `resolve()` now doesn't check if
resolved element is a `PsiMethod` because it doesn't use
`PsiImplUtil#extractUniqueElement`.

Zero chances of meeting 32-bit JRE on macOS versions IDEA can run on.

When base function is located in different module its type hints may
refer types that are inaccessible in the module where overridden
function is located. To prevent unresolved reference error import
statements are added to the module.

This reverts commit ed735310