hs: Rescan the main loop event list if the service map changes

Because ADD_ONION/DEL_ONION can modify the global service map (both for v2 and
v3), we need to rescan the event list so we either enable or disable the HS
service main loop event.

Fixees #25939

Signed-off-by: David Goulet <dgoulet@torproject.org>