Alternate key for activating zones while dragging a window in FancyZones

### Description of the new feature / enhancement

I would like to be able to use the left ctrl key (like in Nvidia RTX desktop manager) to activate zones while dragging.

### Scenario when this would be used?

The shift key needs a finger to activate. The ctrl key can be activated by rolling my palm onto the bottom corner of the keyboard, freeing my fingers for other things.

### Supporting information

This behavior is native in Nvidia's desktop manager.,

Start by locating FancyZones' window-drag activation handling and the existing Shift-key behavior. Trace how modifier keys activate zones, then verify that the left Ctrl key provides the requested alternative without changing current Shift behavior; test the interaction while dragging windows.

Written by the indexing model from the issue text.