widget: Deprecate some style properties
widget: Deprecate some style properties

Deprecate the ::wide-separators and ::separator-width/height
style properties.

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