selftests: net: bridge: add test for igmpv3 inc -> is_exclude report

The test checks for the following case:
   state          report        result                 action
  INCLUDE (A)    IS_EX (B)     EXCLUDE (A*B,B-A)      (B-A)=0
                                                      Delete (A-B)
                                                      Group Timer=GMI

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