app_queue: Preserve reason for realtime queues

app_queue: Preserve reason for realtime queues

When Asterisk is restarted it does not preserve paused reason for
members of realtime queues. This was fixed for non-realtime queues in
ASTERISK_25732

Resolves: #66

UpgradeNote: Add a new column to the queue_member table:
reason_paused VARCHAR(80) so the reason can be preserved.

UserNote: Make paused reason in realtime queues persist an
Asterisk restart. This was fixed for non-realtime
queues in ASTERISK_25732.