known issue: copying images often puts data:image/png;base64 on clipboard

[cablehead]

From @0n0mat0p03ia

Comment: I noticed that selecting Copy from the modal window creates a new clip in the top stack, displaying the base64 encoding of the image (e.g., data:image/png;base64,iVBORw0KGgoAAAANSU...) rather than the image itself. Is this the expected behavior?

[cablehead]

blocked by (in a forcing function sense): #46