Feat/set audit fields via trigger

[dleard]

There are a ton of files changed in this PR. Most of the changes are either adding triggers to models by inheriting the Meta of the Timestamped Model or removing the set_create_or_update() function calls that have been replaced by the triggers.

The "meat" of the work done in this PR to apply triggers is in this one file:

• registration/models/time_stamped_model.py

Most of the relevant tests are in these files:

• conftest.py (one file in each moduel's "test" directory)
• common/tests/utils/helpers.py
• registration/tests/models/test_timestamped_model.py

Bug fix in:

• service/user_operator_service_v2.py