[8021q + bridge] Integration with the CLI
This commit aims to integrate to following operations from bridge+8021q implementation with the CLI:
* vlan_add/vlan_del
* if_set_mode (there is still a problem with setting the interface to IF_ROUTED)
* if_add/if_remove
* if_set_port_vlan
* if_get_type
* if_enable/if_disable (currently it works fine for IF_SWITCHED interfaces)
* get_if_list
* if_get_cfg
* get_vlan_interfaces
* get_vdb
* if_(add/set/del)_trunk_vlans (still must return appropiate errors here)
* vif_add/vif_del
We still need to make some apropriate changes to the lisa backend implementation, i will make this changes later this night.

Signed-off-by: Victor Duta <duta.victor.marin@gmail.com>