D9817: Adapt to QQuickWindow hover event synthesis & optimize delegate

[Eike Hein]

hein added a reviewer: broulik.

REPOSITORY
  R119 Plasma Desktop

REVISION DETAIL
  https://phabricator.kde.org/D9817

To: hein, #plasma, broulik
Cc: plasma-devel, ZrenBot, progwolff, lesliezhai, ali-mohamed, jensreuterberg, 
abetts, sebas, apol, mart