StaticImport hint should support records and other class kinds

[mbien]

uses javac's Element.getKind().isClass() as filter which matches all class kinds.

minor code improvements and indentation fixes

note: the hint is disabled by default

fixes #9166

[lahodaj]

Hmm, I wonder if the klass.getKind() != ElementKind.CLASS / !klass.getKind().isClass() should even be there. I don't see a reason why the hint should not be working inside e.g. default interface methods? In other words, I am unclear why this restriction was there originally. The hint predates default interface methods, I think, but even before that, interfaces were allowed to have static final fields with initializers?

[mbien]

Hmm, I wonder if the klass.getKind() != ElementKind.CLASS / !klass.getKind().isClass() should even be there. I don't see a reason why the hint should not be working inside e.g. default interface methods?

good point. isClass() || isInterface() sounds like the safe option for now, in case more types show up in future like module files or something like that?

will update it

[mbien]

will rebase on top of the CI fixes to try to get a green build

[ebarboni]

looks green.