Homogenise close icon buttons and make them visually distinguishable when hovered
Problem/Opportunity Statement
The close icon button should be as in DataList widget's dropdown & chips (non-outlined, clean, using active UI state's color).
But it differs in places like Toast widget (and maybe others?). It should be same as others - in toast widget, it can take text color of toast state.
Besides this, these close icon buttons are non-outlined/borderless (elm-ui-widgets' iconButton
material style) so there isn't any noticable change in their visual state when hovered. We can either darken/lighten the icon color (as in PF) or make their transparent background colored (as in Gmail).
What would success / a fix look like?
Make a close icon button widget that addresses all of the above points. It will be even better to make it as a special case of a more generalised non-outlined icon button widget that can do any icon besides "X".