This is the first step in trying to add context/right-click menus to different tools. This one is for most of the selection tools (except bezier because that is going to need a bigger change to get that working I think).
There is at least one wishlist item with the selection tools specifically
https://bugs.kde.org/show_bug.cgi?id=337380
I am not sure of the exact list of the right click options are final, but those can be changed easily enough.