)

## Summary

Completes related tickets:
#180160 and
#180158

Switches fields to use the diff algorithms assigned to them in the
related tickets

Adds integration tests in accordance to
#184484 for the `upgrade/_review`
API endpoint for the simple diff algorithm.

Also changes logic in the `upgrade/_review` API endpoint to return user
customized fields in the diffs even if there was not an update for that
field. This new logic is described in
#180154. We filter out the
fields that fall under this new logic so that they are only returned
from the API but not displayed in the per-field rule diff flyout as the
current UI cannot support them. They are utilized in testing logic and
will be implemented in the UI at a later date

### Checklist

Delete any items that are not applicable to this PR.

- [x] [Unit or functional
tests](https://www.elastic.co/guide/en/kibana/master/development-tests.html)
were updated or added to match the most common scenarios
- [x] [Flaky Test
Runner](https://ci-stats.kibana.dev/trigger_flaky_test_runner/1) was
used on any tests changed

### For maintainers

- [ ] This was checked for breaking API changes and was [labeled
appropriately](https://www.elastic.co/guide/en/kibana/master/contributing.html#kibana-release-notes-process)

---------

Co-authored-by: Kibana Machine <42973632+kibanamachine@users.noreply.github.com>