Let Ctrl+click cycle through selection of overlapping elements
In the spirit of the usability tweak in #284385: Let right-click toggle between adding rests and notes, I also propose modifying the behavior of Ctrl+click slightly. Currently, it adds an element to a list selection if it is not already selected, removes it if it is selected. I want to keep that but add something to the latter case: if the clicked element is currently selected but also overlaps another another element, we would not only deselect the current element but also select the element underneath. Thus making it easy to cycle through a stack of overlapping elements. Once you reach the end of the stack it would continue to get deselected.
I already wrote the code for this some time ago, just need to update it for 3.0