The launcher applets couldn't be closed with Meta alone and on Wayland
in general by any global shortcut, since we used for that the focusOutEvent
triggered only on X and only on global shortcuts (on default Alt+F1).

This patch introduces the new bool activationTogglesExpanded, which allowes
QML applets to decide if they wish to use the activated signal also to end
their expanded state.

The default value is false, in order to not break any legacy applets.

REVIEW: 129204
BUG: 367685