Add ModuleInfoBackedContext loading strategy to RuntimeGeneratedMapping service.

RuntimeGeneratedMappingServiceImpl is now started by the config-manager.
ModuleInfoBackedContext is filled by BundleTracker in config-manager.

This fix allows use of yang identities in netconf and restconf.

Change-Id: Id59d9d2ce08bfc9216d90cb5673e2d02aafd9151
Signed-off-by: Maros Marsalek <mmarsale@cisco.com>