lists: Mark domains as listed for faster search

lists: Mark domains as listed for faster search

The query that is determining which domains are whitelisted has always
been very slow and there is no feasible way to accellerate it using
indexes, etc.

Therefore we will download all whitelisted domains and all potentially
blockable domains and perform the check in the Python application. That
way, we can later mark any delisted domains and fetch the entire list of
domains reasonably fast.

Signed-off-by: Michael Tremer <michael.tremer@ipfire.org>