Update brg topo activate DG

1. Use get-resource sql plugin
to get wan-brg-ip using wan-brg-mac

2. Changed call to brg-wan-ip-address
to correct variable

3. Added DG get-vgmux-lan-ip and used
new DG in brg topo activate to get
vgmux-lan-ip from md-sal using
consuming-service-instance-id as key

Issue-Id: SDNC-181
Change-Id: I1448cfbcc94f66dc7c2a854d0013ccc443b4e420
Signed-off-by: Marcus G K Williams <marcus.williams@intel.com>