'can't give feedback' button does not clear textanswers

[Kakadus]

To skip evaluating a contributor and select "no answer" for all its questions, the "I can't give feedback about this contributor" button can be used. If the user changes a radio input value, this button gets activated again.

After clicking this button, textanswers for that contributor are still submitted, which might be unexpected.
When the contributor only has textanswers, the button is useless and cannot be activated again after being clicked once.

Instead, all textanswers for that contributor should be cleared as well - also textanswers attached to rating questions. Also see #2302 (comment). When the user edits a textanswer, this button should be activated again.

[janno42]

After clicking the button, a confirmation modal should be displayed to confirm the deletion of the text answers to avoid losing valuable data if text answers have already been entered for that contributor.