Add support of upload of a list of image URLs

[zabak]

• txt (one URL per line)
• IIIF manifest (IIIF is an internetional standard, IIIF Presentation API manifest can contain a list of pages with links to IIIF image API - API specification https://iiif.io/api/presentation. Example manifest: https://iiif.wellcomecollection.org/presentation/v2/b20457558

[zabak]

Can be solved using the #70