prevent database deadlocks #6846 #6865 #7020

[pdurbin]

What this PR does / why we need it:

The pull request adds a sleep right before the UPDATE DVOBJECT SET INDEXTIME happens which sometimes leads to database deadlocks, especially when the full API test suite is run. This method is called after indexing.

Which issue(s) this PR closes:

Closes #6846 Test Failing
Closes #6865 Internal Exception: org.postgresql.util.PSQLException: ERROR: deadlock detected
Closes #7020 Get API test suite passing 😴 😴 😴

Special notes for your reviewer:

• The 3 second sleep is hard coded.
• On a test run it now takes 18:18 min to execute the test suite. On develop on the same box it took 4:21 min.

Suggestions on how to test this:

Deploy the branch. See if the 3 second sleep is bothersome, especially during normal user operations and indexing.

Does this PR introduce a user interface change? If mockups are available, please link/include them here:

No.

Is there a release notes update needed for this change?:

No.

Additional documentation:

None.

[coveralls]

Coverage decreased (-0.0008%) to 19.652% when pulling c68ab9c on 7020-timestamp-sleep into c5c2236 on develop.

[pdurbin]

At tech hours yesterday we talked about a new lead that the deadlock may happen between setting the index time and setting the permission time. Closing. People should keep an eye on #6865.