Feature Install ODL-RESTCONF does not install ietf-restconf model

When you install just the odl-restconf feature you are not able to access /modules or /streams or /operations etc because the ietf-restconf yang file can not be found. THis is because we don't ship the ietf-restconf bundle as part of the odl-restconf feature or dependent feature.

Fix: we need to make sure that the ietf-restconf bundle is installed when the odl-restconf feature is installed.

To reproduce:

Start a clean karaf distro in which you have access to the odl-feature feature (controller distro should work).

Do a "feature:install odl-restconf"
Try to go to localhost:8181/modules or localhost:8181/operations - you get an error about a missing module.