Canvas: support Ctrl + Drag link to local file for canvas

Currently, this only works for note not canvas. Please consider make available for canvas.

Use case or problem

To use canvas as pin/mood/concept board from external image (ex. image management software) would be very helpful.

Proposed solution

As title

Current workaround (optional)

Ctrl Drag image to note, then copy the link to canvas card

Related feature requests (optional)