Use "outcome" to indicate pending record

Use "outcome" to indicate pending record

Mariadb is setting the "endtime" to the current time by default,
so rather than indicate a pending record using a null endtime, just
modified the code set "outcome" to "Started" to indicate a pending record.
Also added code to ensure the "outcome" is never null, as that causes
a DB error.
Also addressed a comment from a previous review to log a warning message
if more than one matching record is found in operations history.

Issue-ID: POLICY-2581
Change-Id: I6bf67551cef46808a79cc15afeb0abbfc1b6d945
Signed-off-by: Jim Hahn <jrh3@att.com>