Adds the --<goal>-use-source-root for IDE project generation tasks.

The option will put one entry for each source_root registered that has an active path in the project.
This is useful for Maven style layouts.

Testing Done:
Added unit test and integration test.

Manually tested with:

  pants goal idea testprojects/maven_layout:: --idea-use-source-root

CI is running.

Bugs closed: 558

Reviewed at https://rbcommons.com/s/twitter/r/1006/