Fix Accessibility warnings by missing labels in Widget table cells

Added some additional labels in the widgets.

Please test the resulting code in Dev-version or the upcoming 1.8 version, and report back.

Perhaps the labels are not fluent, should be translated(?), or duplicate the element.
For instance, I see the hours are marked in the browser with 'no-label'.
The weekdays may not need a label, either. Of so. not sure how to accomplish that.
The above patch removes the warnings b Chrome DevTools:
"Accessibility: Form elements must have labels: Element has no title attribute Element has no placeholder attribute"

Let's close this, assuming current code is up-to date for the requested functionality.