net: bridge: multicast: add EHT allow/block handling

Add support for IGMPv3/MLDv2 allow/block EHT handling. Similar to how
the reports are processed we have 2 cases when the group is in include
or exclude mode, these are processed as follows:
 - group include
  - allow: create missing entries
  - block: remove existing matching entries and remove the corresponding
    S,G entries if there are no more set host entries, then possibly
    delete the whole group if there are no more S,G entries

 - group exclude
  - allow
    - host include: create missing entries
    - host exclude: remove existing matching entries and remove the
      corresponding S,G entries if there are no more set host entries
  - block
    - host include: remove existing matching entries and remove the
      corresponding S,G entries if there are no more set host entries,
      then possibly delete the whole group if there are no more S,G entries
    - host exclude: create missing entries

Signed-off-by: Nikolay Aleksandrov <nikolay@nvidia.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>