[CLEANUP] Avoid Hungarian notion for the Commentable interface

[oliverklee]

Also adapt the implementing classes accordingly.

Part of #756.

[coveralls]

coverage: 42.138%. remained the same
when pulling ca9b608 on task/hungarian-4
into 540b315 on main.

[JakeQZ]

I can't help but notice that the various classes implementing Commentable seen to have exactly the same implementation. So I think this could be tidied up by providing a trait for a 'standard' Commentable implementation - but is beyond the scope of this PR.

[JakeQZ]

I can't help but notice that the various classes implementing Commentable seen to have exactly the same implementation. So I think this could be tidied up by providing a trait for a 'standard' Commentable implementation - but is beyond the scope of this PR.

Added #813 to capture this.