WIP: Move protected branches by user feature to CE

What does this MR do?

Currently in EE-only you can override protected branch settings on a per-user basis. This MR will move this functionality down into CE.

Screenshots

Does this MR meet the acceptance criteria?

Conformity

• Changelog entry
• Documentation (if required)
• Code review guidelines
• Style guides
• Separation of EE specific content

Availability and Testing

• Review and add/update tests for this feature/bug. Consider all test levels. See the Test Planning Process.