Add ConfigurationAction
This is a rework of CategorizedSettings, visually it looks the same on desktop and on mobile there is some small visual changes to match plasma-settings.
The API is almost the same with the exeption that ConfigurationAction is a plain Kirigami.Action while CategorizedSettings was a Kirigami.PageRow. This means ConfigurationAction will take care of opening itself with its open method while opening a CategorizedSettings was the responsability of the application developer.
This is motivated by the recent breakage of CategorizedSettings on desktop and the less recent breakage on mobile which were not fixable with the same API. All the internals are not exposed so it is easy to in the future change the visual if needed.
Edited by Carl Schwan