Improve Image and Presentation API compatibility

[lutzhelm]

• Use image resolution from info response instead of Canvas - Image service may have a different resolution than the Canvas
• Use correct canonical image size URL parameter (full vs. max / w, vs. w,h) dependent on IIIF Image API version
• Offer manifest renderings for download, not only sequence renderings
• Ensure that the offered download links do not exceed maxArea / maxWidth / maxHeight
• Fix IIIF Presentation 3 not supported #63 along the way
• Offer any existing static image URL if no image service is present

The plugin also does not offer a download for every image service beyond the first; this will need to be adressed outside this PR. -> #91

[phil-plencner-hl]

Hi @lutzhelm,

At Harvard we recently discovered were are having the same issue with version 3 iiif manifests returning inaccurate download links. I tried some of our manifests against this branch and they work correctly. Here are the ones I tried:

• https://nrs.harvard.edu/URN-3:FHCL:103496523:MANIFEST:3
• https://nrs.lib.harvard.edu/URN-3:FHCL:29400954:MANIFEST:3
• https://nrs.lib.harvard.edu/URN-3:FHCL.LOEB:25853480:MANIFEST:3
• https://nrs.harvard.edu/URN-3:FHCL:106214677:MANIFEST:3

The version 2 iiiif manifests of the same objects also continue to work correctly on this branch:

• https://nrs.harvard.edu/URN-3:FHCL:103496523:MANIFEST:2
• https://nrs.lib.harvard.edu/URN-3:FHCL:29400954:MANIFEST:2
• https://nrs.lib.harvard.edu/URN-3:FHCL.LOEB:25853480:MANIFEST:2
• https://nrs.harvard.edu/URN-3:FHCL:106214677:MANIFEST:2

From my perspective this is working and can be merged. Is that something we can do, or should we bring it up at the next Mirador Community Call?

cc: @marlo-longley @cbeer

[phil-plencner-hl]

I'm also wondering if there is a way to port these changes to a Mirador 3 compatible version of the plugin? We have not upgraded to 4 yet, but would like the download bug fix if possible.