[eclipse-pmc] API addition request: discover the OSGi Bundle behind a re

[Oleg Besedin <obesedin@xxxxxxxxxx>]

Multiple requests were submitted to
provide a more convenient way to find OSGi bundle corresponding to a registry
contribution.

GOALS/BENEFITS:
- provides a method to find the OSGi
bundle for a registry contribution. While it is possible to do now, the
new method eliminates the need for a user to dive into registry implementation
details
- reduces usage of the org.eclipse.core.runtime.Platform
class, and, hence, the org.eclipse.core.runtime bundle

CORRESPONDING BUG:
- “need a way to avoid Platform”
        https://bugs.eclipse.org/bugs/show_bug.cgi?id=130841

RISKS:
- No known risks

PERFORMANCE IMPACTS:
- No impact

This is a non-breaking API change as
we are adding a new method to the "final" class.

Thanks,
Oleg