[GITHUB-9056] Using sharp(er) classpath when rename refactoring.

[lahodaj]

The Java refactoring is sometimes using class path (ClasspathInfo) that is, to me, extremely weird. In the specific case of #9056, the ClasspathInfo used to process GspIndenter does not in some cases contain the lexer module, while the groovy/groovy.gsp definitely lists it as a dependency.

The consequence of that is that there are compile-time errors in the file(s) with this broken class path. Sometimes, it may lead to "catastrophic" failures like:
https://bugs.openjdk.org/browse/JDK-8373094

but even if it does not, wrong class path is likely to lead to weird effects.

The goal of this prototype is to use class path that is more sensible for the rename refactoring. I have some idea for an automated test showing the difference, but I don't have that written yet.

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