builtinicon: Change the way size is handled
builtinicon: Change the way size is handled

Make min-width/height have preference over the set default size. This
allows shrinking the widget. The default size is only used if min-width
is not set (or explicitly set to 0.

grubersjoe/adwaita,grubersjoe/adwaita,grubersjoe/adwaita,grubersjoe/adwaita,grubersjoe/adwaita,grubersjoe/adwaita,grubersjoe/adwaita,grubersjoe/adwaita