Provide a Gazelle extension for BUILD file generation

[alexeagle]

Gazelle is the standard tool in the Bazel ecosystem to relieve developers of most of the burden and toil associated with BUILD files.

This repo seems like the obvious place for it to live, since the implementation of the rules is closely related to generation of those rules. This would follow the precedent of https://github.com/bazelbuild/bazel-skylib/tree/main/gazelle and https://github.com/bazelbuild/rules_python/tree/main/gazelle

Another option would be to discuss with maintainers about placing it over here next to Java https://github.com/bazel-contrib/rules_jvm/tree/main/java/gazelle which is already discussed in an open issue bazel-contrib/rules_jvm#126

https://github.com/bazel-contrib/bazel-gazelle?tab=readme-ov-file#supported-languages is a listing of common ones, and Kotlin is there - @jbedard implemented that over here https://github.com/aspect-build/aspect-cli/tree/main/gazelle/kotlin with funding from @gonzojive. We're considering donating that code, so I'm soliciting input on where we might want it.

[restingbull]

This is already in discussion here.

[restingbull]

After discussion with the current maintainers, we are not currently capable of taking on maintaining a gazelle plugin at this time.

The kotlin gazelle examples, aspect and proposed rules_jvm have no overlap with the rules_kotlin code base.