Fully perform at IIIF Validator

[nichtich]

At https://iiif.io/api/image/validator/ with IIIF Image API 3.0, all tests are green except:

• Check Image Information http://uri.gbv.de/iiif/67352ccc-d1b0-11e1-89ae-279075081939/info.json, got: level3, expected: http://iiif.io/api/image
• Random format gives 400, http://uri.gbv.de/iiif/67352ccc-d1b0-11e1-89ae-279075081939/full/max/0/default.D\R, got: Expected [400, 415, 503] for status; Got: 200
• PDF format
• WebP format
• JEPG2000 format
• canonicalLinkHeader (redirect instead)
• profileLinkHeader (implemented but broken?)

[nichtich]

PDF, WebP, and JPGE2000 format are delivered by not recognized properly by the validator - need to check back with validator authors what is actually tested.