:sparkles: [#4344] Configurable objects API group in ZGW registration

[stevenbal]

previously this was not configurable and always used the ObjectsAPIGroup with the lowest pk to create the client when registering the submission

Closes #4344

Changes

• Configurable objects API group in ZGW registration

Checklist

Check off the items that are completed or not relevant.

• Impact on features

  • [x] Checked copying a form
  • [x] Checked import/export of a form
  • [x] Config checks in the configuration overview admin page
  • [x] Problem detection in the admin email digest is handled

• Release management

  • [x] I have labelled the PR as "needs-backport" accordingly

• I have updated the translations assets (you do NOT need to provide translations)

  • [x] Ran ./bin/makemessages_js.sh
  • [x] Ran ./bin/compilemessages_js.sh

• Commit hygiene

  • [x] Commit messages refer to the relevant Github issue
  • [x] Commit messages explain the "why" of change, not the how

[codecov[bot]]

Codecov Report

All modified and coverable lines are covered by tests :white_check_mark:

Project coverage is 96.57%. Comparing base (c50aa99) to head (9abd733). Report is 14 commits behind head on master.

Additional details and impacted files

```diff @@ Coverage Diff @@ ## master #4758 +/- ## ========================================== + Coverage 96.55% 96.57% +0.01% ========================================== Files 748 748 Lines 25423 25448 +25 Branches 3362 3369 +7 ========================================== + Hits 24548 24576 +28 + Misses 610 608 -2 + Partials 265 264 -1 ```

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[stevenbal]

I tested the import locally, I did notice that there seems to be an issue when exporting/importing a form that has the legacy zaaktype empty, it is not present in the export and causes errors when importing:

I think it's unrelated, so I'll create a separate issue for it https://github.com/open-formulieren/open-forms/issues/4779