log-iter-pidgin: Implement get_events
log-iter-pidgin: Implement get_events

It a sign of completion if the number of events returned is less than
num_events. NULL is returned when there are no more events left in the
log.

Fixes: https://bugs.freedesktop.org/41772

freedesktop-unofficial-mirror/telepathy__telepathy-logger,freedesktop-unofficial-mirror/telepathy__telepathy-logger,freedesktop-unofficial-mirror/telepathy__telepathy-logger