net: bridge: vlan: dump mcast ctx querier state

Use the new mcast querier state dump infrastructure and export vlans'
mcast context querier state embedded in attribute
BRIDGE_VLANDB_GOPTS_MCAST_QUERIER_STATE.

Signed-off-by: Nikolay Aleksandrov <nikolay@nvidia.com>
Signed-off-by: David S. Miller <davem@davemloft.net>