pimd: Implement rpf lookup mode as a list

pimd: Implement rpf lookup mode as a list

Add the support to store lookup modes as a sorted list.
List is non-unique and sorts mode with both lists < modes with one list < global mode (no lists).
This way, when finding the right mode, we will match a lookup using a prefix list before the global mode.
Add passing group address into all lookups (using nht cache and/or synchronous lookup).
Many areas don't have a group address, use PIMADDR_ANY if no valid group is needed.

Signed-off-by: Nathan Bahr <nbahr@atcorp.com>