L3VLAN capability assign IP address

Fixes:
* [OPENNAAS-1375](http://jira.i2cat.net/browse/OPENNAAS-1375)
* [OPENNAAS-1376](http://jira.i2cat.net/browse/OPENNAAS-1376)
* [OPENNAAS-1377](http://jira.i2cat.net/browse/OPENNAAS-1377)