feat(kcm): add revert timer

Updated Version of Feature Add Revert Timer with these additional Changes

• Exposes A bug in system settings that after hitting apply a kcm loses activeFocus.
  • Can not force keyboard focus to the revert dialog
  • Action Shortcuts function correctly.
• Rebased, Cleaned Commits.
• New private method bool ConfigHelper::checkSaveandTestCommon(bool isSaveCheck)
  • used as a common back end for ConfigHelper::checkNeedsSave and ConfigHelper::shouldTestNewSettings
• Use "Configuration" consistently
• Cleaned up some Zixing Liu 's code
• Use function OnFoo style Connection Type
• Addressed the open threads
  • Do not prompt to keep configuration if the scale changed on X11.
  • Do not prompt when changing the way the config is stored
• Use Kirigami OverlaySheet for a cleaner dialog
  • 
  • Use Enter and Escape as action shortcuts along with Alt+K / Alt+R