Rename comments tab to feedback

[magdalenadrafiova]

@xsrust
Differentiate comment and structured feedback so it is more obvious to the users

[xsrust]

The comments we got were around this feature being used more for the review/feedback workflow than for collaboration via notes.
One suggestion was to rename the tab, and another just to differenciate the two visually.

[pherterich]

Current suggestion for highlighting admin comments visually - grey background and boarder in the tailored colour. Introduced at the demo session today.