Hover enter/leave events regression

Regression from Qt 6.0 to 6.2: Clients running inside a QtWayland-based compositor that uses WaylandMouseTracker, will receive one enter and one leave event for each mouse move. This can be reproduced by running the attached enterleave.qml as a wayland client against the pure-qml example compositor. This issue also causes visible flickering when running  e.g. qtbase/examples/widgets/widgets/calculator inside pure-qml.

This issue does not only happen on the client side. It also seems to happen inside the compositor, with QML items that are part of server side decorations.

Update: There seems to be two separate issues:

1. WaylandCursorItem has an item for the drag icon. This item gets an extra enter/leave for each mouse event. This is easily fixed by disabling input events for the corresponding WaylandQuickItem. This is a compositor-side problem.
2. With the attached enterleave.qml, there are occasional events with a different position. This is a client side issue, since it can also be reproduced when running on Weston