feat: Add versioning actions to settings (admin change view) of versioned objects

[fsbraun]

Description

This PR adds standard versioning actions to the change of view of versioned objects, including page contents:

This includes a "New Draft" button for published versions:

Further improvements:

• "Versions" button takes the user to the version list.
• The version list includes a new settings action for frontend-editable versioned objects to be able to see the settings historic objects (such as meta tags for unpublished versions)

(For not frontend-editable objects, the "View" button already takes the user to the change view and no settings button is offered.)

Finally, this PR fixes a bug that prevented users from editing slugs in some cases. (https://github.com/django-cms/django-cms/issues/7866)

Related resources

• https://github.com/django-cms/django-cms/issues/7866
• #...

Checklist

• [x] I have opened this pull request against master
• [ ] 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.