Fix monitor race condition
From the main commit:
libtracker-miner: Handle race condition in renaming directories
When a recursively indexed directory is renamed, we have 2 ongoing
events: G_FILE_MONITOR_EVENT_DELETED from the GFileMonitor set in the
directory itself, and G_FILE_MONITOR_EVENT_RENAMED from the parent
directory GFileMonitor.
When a directory is renamed, we have to throw away the monitors in the
old location, and add them back in the new location. This sometimes
happens right in time to ignore the DELETED event, and sometimes it
doesn't.
Add a short-lived caching of DELETED events, so we can handle those
situations correctly. If the DELETED event corresponded to this situation
the event would be silenced away, otherwise it would be emitted in an
idle callback.
Fixes: https://gitlab.gnome.org/GNOME/tracker-miners/-/issues/92