Rename OSGi classes for Java naming conventions (#9320)
- Rename OSGi to Osgi in class names.
- Rename VaadinOSGiPortlet to OSGiVaadinPortlet for consistency with
Spring, CDI etc. add-ons
- Add missing javadoc
Remove dependency of portlets to liferay-integration bundle
A property can be used instead of the convenience annotation to mark a UI
as a Portlet UI registration that should be picked up by the liferay
integration. This removes the unnecessary dependency on the liferay-integration
bundle.