[IMPROVEMENT] - Improve ban buttons

[janssensjelle]

Types of changes

What types of changes does your code introduce?
Put an x in the boxes that apply.

• Bugfix (non-breaking change which fixes an issue).
• New feature (non-breaking change which adds functionality).
• Breaking change (fix or feature that would cause existing functionality not to work as expected).
• Documentation Update (if none of the other choices applies).

Proposed changes

This PR improves the usability from the ban decision buttons.

• Approve can only be clicked once
• Disapprove can only be clicked once (will grey out all buttons as the user is unbanned immediately

Checklist

Put an x in the boxes that apply.

• I have read and followed the CONTRIBUTING.md
  doc.
• Lint and unit tests pass locally with my changes.
• I have added the necessary documentation (if appropriate).

Additional context

Add any other context or screenshots here.

[dimoschi]

Solid improvement!