Fix cache sync issues with QtQuick dialog
The engine is reused for the QtQuick dialog, consequently the cache gets only updated once the dialog is initialized. Now the cache is updated if the RemoveDeadEntries option is selected every time every time the dialog is about to show.
Also the state of the entries gets updated and with 8531bbcc the current filter re-validates these entries properly.
BUG: 417985
FIXED-IN: 5.74