[BBR] Apply downstream multicast config sent from ot-daemon

The multicast listening address from ot-daemon is maintained separately
from the bbr state. When bbr changes from primary to secondary, there
can still be subscribed addresses and should not be missed when switching
back to primary mode. So instead of sending address add/remove events
from ot-daemon and maintain the list in system server, ot-daemon will
send full list of addresses together with the multicast routing
enablement state each time there is an update to the bbr state or
listening addresses.

Bug: 321624274

Test: atest ThreadNetworkIntegrationTests

Change-Id: Ic9ce77bb7fdeacf2def216cf9bcd44095083a992