In order to process IGMPV3/MLDv2_MODE_IS_INCLUDE/EXCLUDE report types we
need some new helpers which allow us to set/clear flags for all current
entries and later delete marked entries after the report sources have been
processed.

v3: add IPv6/MLDv2 support
v2: drop flag helpers and directly do flag bit operations
Signed-off-by: Nikolay Aleksandrov <nikolay@cumulusnetworks.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>