fix: Update templates for better styling w/o djangocms-admin-style

Description

This PR adds the .submit-row <div> used in Django admin for more consistent styling.

It also removes an unused left-over helper function (legacy of pre-2.0):

djangocms_verisoning.helpers.remove_published_where(qs) used to patch a queryset removing the resulting SQL WHERE statement which restricts the queryset to include published versions only.
It is not used in the codebase any more. Usage in djangocms-alias has been removed a while ago.
The official pattern is to use the admin_manager of a versioned model which as the name indicates should only be used in the admin.

Related resources

Checklist

[x] I have opened this pull request against master
[x] I have added or modified the tests when changing logic
[x] I have followed the conventional commits guidelines to add meaningful information into the changelog
[x] I have read the contribution guidelines and I have joined #workgroup-pr-review on Slack to find a “pr review buddy” who is going to review my pull request.

Codecov Report

Patch coverage: 100.00% and project coverage change: +0.21% :tada:

Comparison is base (5944cff) 90.69% compared to head (3204c1b) 90.90%.

:exclamation: Current head 3204c1b differs from pull request most recent head bf1c6bf. Consider uploading reports for the commit bf1c6bf to get more accurate results

Additional details and impacted files

```diff @@ Coverage Diff @@ ## master #352 +/- ## ========================================== + Coverage 90.69% 90.90% +0.21% ========================================== Files 72 72 Lines 2536 2530 -6 Branches 357 356 -1 ========================================== Hits 2300 2300 + Misses 175 170 -5 + Partials 61 60 -1 ``` | [Files Changed](https://app.codecov.io/gh/django-cms/djangocms-versioning/pull/352?src=pr&el=tree&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=django-cms) | Coverage Δ | | |---|---|---| | [djangocms\_versioning/helpers.py](https://app.codecov.io/gh/django-cms/djangocms-versioning/pull/352?src=pr&el=tree&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=django-cms#diff-ZGphbmdvY21zX3ZlcnNpb25pbmcvaGVscGVycy5weQ==) | `91.11% <100.00%> (-0.29%)` | :arrow_down: | ... and [1 file with indirect coverage changes](https://app.codecov.io/gh/django-cms/djangocms-versioning/pull/352/indirect-changes?src=pr&el=tree-more&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=django-cms)

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django-cms / djangocms-versioning