Crop gets clamped to image size, but uses full width/height

[RobertMueller2]

Version

0.20.0

Description

Repro:

1. resize satty so there is some spare area on canvas
2. crop from outside of the image, I assume it can only be reproduced with x < image x offset and y < image y offset

Expected:
Saved image should be the intersection between crop area and the image*

Actual:
Crop offset is moved, but width or height remain unchanged

*) I know we may want to save a larger image if there are annotations on the canvas outside of the image, I think we need to discuss that feature first, though.