Investigate replacing leaflet-iiif with another cropping library

[marlo-longley]

Related to #2961

project was last released in 2019 https://github.com/mejackreed/leaflet-iiif

[marlo-longley]

From Steve: I also think we'd want to avoid dramatically changing behavior to the point where we'd want to do a whole design review.

[cbeer]

I think the key features of the current cropper are:

• allowing the user to zoom + pan around an image
• support fixed-aspect cropping modes
• zooming + panning should not change the any selected cropped area
• not-too-heavyweight (e.g. pulling in all of Mirador isn't ideal.)

[dnoneill]

Couple approaches we could do:

1. Create our own OpenSeadragon listener that would draw
2. https://github.com/tuvia-r/openseadragon-select-plugin/tree/main (2 years is the last update which isn't great)
3. https://annotorious.dev/getting-started/ customize annotorious viewer.
4. https://github.com/dpb587/iiifimage.link
5. OpenLayers https://openlayers.org/en/latest/examples/iiif.html (use shift. It zooms but should be easy enough to edit, I think)

[marlo-longley]

Another great option could be https://github.com/dbmdz/mirador-imagecropper This is developed and used by our colleagues at Leipzig, who are currently also working to make it compatible with Mirador 4.