[dashboard] Refactoring some common code
[dashboard] Refactoring some common code

Class BgpvpnTable between admin and project panel has
some common code. This patch inherit BgpvpnTable class
from project in BgpvpnTable Admin table.

Change-Id: I6c59f79334ef22afb8160aee44c244c6f5fc9b15

openstack/networking-bgpvpn,openstack/networking-bgpvpn,openstack/networking-bgpvpn