kcms/xwayland: Add settingStateBindings
This adds the orange highlights of which settings are changed within the KCM.
The KCFG file is modified as QML bindings automatically convert properties to lowerTitleCase, but then the settingName in the SettingStateBinding is not and people spend ages debugging it. Writing it explicitly makes it clearer. The config file format is unchanged.
(cherry picked from commit a4856a01)
Co-authored-by: David Edmundson kde@davidedmundson.co.uk