Add bnd-parent

We are providing bundle-parent to generate OSGi metadata in MANIFEST.MF using bundle-maven-plugin.

That plugin has a few deficiencies, like taking over the maven-jar-plugin's job, requiring explicit packaging and doing things that are generally not needed.

There is a better alternative in the form of bnd-maven-plugin, which is provided by the fine folk over at https://bnd.bndtools.org/ , which is the same technology bundle-maven-plugin uses.

While the differences in pom.xml are superficial, the set of capabilities and defaults more closely matches OSGi intent.

Provide a separate bnd-parent which will come with pre-configured bnd-maven-plugin and allow downstreams to migrate.