SCIP ctags: improve 'kind' output

[jtibshirani]

In https://github.com/sourcegraph/sourcegraph/issues/57659 we noticed that SCIP ctags assigned very general kinds compared to universal-ctags, missing important information needed for search ranking. This is a follow-up issue to improve SCIP ctags for the remaining languages it supports:

• Go https://github.com/sourcegraph/sourcegraph/pull/57806
• C https://github.com/sourcegraph/sourcegraph/pull/58082
• C++
• Java
• Scala
• Zig

I'm spinning this out of the original issue #57659 since there's no search regression for these languages: either universal-ctags never supported them (Scala, Zig), or we hadn't enabled SCIP ctags yet (C, C++, Java). Once we're confident in the output, we can also enable SCIP ctags for C, C++, Java.