Add an ability to change bed leveling path directions

Hi. It would be great if we somehow have an ability to define bed leveling path’s start corner and directions as well. This could be handy to eliminate leaked filament to get in the path of the probe.

My example:
I have my BL-Touch probe sitting to the left from the nozzle. Default Klipper leveling path starts at lower left corner and then it does leveling in these directions: right → top → left → top → right etc. So when it moves right there is a chance to measure not the table surface but leaking filament’s “surface” from the nozzle.

So if we could somehow set this path in settings for example:
leveling_position_start: 230, 230
leveling_direction_path: up, left, down, left

See? When we start at the bottom right corner and then move our printhead in these directions: up, then left, then down then left and repeat we eliminate chances of leaked filament to be “measured” with the probe because nozzle is always behind the probing path!