Crop-fit or letterbox-fit, not stretch-fit for non-square images

[joedf]

Konva example: https://konvajs.org/docs/sandbox/Scale_Image_To_Fit.html

[joedf]

Intention is to add fit and fill modes.

Possible examples

• https://konvajs.org/docs/sandbox/Scale_Image_To_Fit.html
• https://konvajs.org/docs/clipping/Clipping_Regions.html

Could use either something with Image.crop() or Group.clip()...