Mode for PathView to allow dragging beyond the path end

Dragging an item in PathView seems to be trying to find closest point on the path as the 'current' location. When dragging past the end of the path, the item stops at the end of the path.

This is usually probably fine, but maybe it could be extended with a mode that allows dragging past the end (ie. the path is extrapolated at the ends) so that the current item wraps around.

It would feel more natural in a case where the path does not cover the whole screen.