Seperate core into core and api modules

[virustotalop]

Issue: We have a lot of dependencies which cluttered downstream projects class path when they pull in core as a dependency.
Solution: Make implementations included in core and then have an api module that only holds interfaces
Tasks:

• Separate core and api modules
• Remove builders, package under class they build for
• Restore parser after abstracting parser code
• Cleanup references to SimpleGuiManager.get()