What does this PR do?

• Adds support for cg resolution of signature-polymorphic methods found in java.lang.invoke.MethodHandle and java.lang.invoke.VarHandle.

Linked issue (if any)

• Fixes [Feature]: Investigate varargs parameter in the call graph algorithm #1266
• Fixes Create Backport for MethodHandle/VarHandle #78

Checklist

Code style & guidelines

• I ran the formatter: mvn com.spotify.fmt:fmt-maven-plugin:format
• I added the necessary comments in the code
• I provided meaningful tests for my proposed change
• I updated documentation (if needed)

Self-review

• I performed a self-review of my code
• I added or updated tests where needed
• I have successfully run tests with your changes locally
• My branch is up to date with develop

Review

• CI checks are green
• I requested a review from a core contributor