mgr/callhome: persist operations between mgr restarts

mgr/callhome: persist operations between mgr restarts

Currently the operations dictionary is only kept in memory. It is lost
when the mgr restarts, and this can cause the module to handle upload
requests which were already processed and registered in the operations
dictionary. To prevent that, we write the operations to the db, and load
them when the module starts.

Resolves: rhbz#2320831

https://bugzilla.redhat.com/show_bug.cgi?id=2320831

Signed-off-by: Yaarit Hatuka <yhatuka@ibm.com>
(cherry picked from commit 9a28b7c97467ede85afdb8d71a19b0d7be124280)
(cherry picked from commit c5a8a8b89b8f9a548ffae072c5bbe85d6bfe77b2)