Expose ImageServer.version in ListProcessElements and StartWorkerActivity

https://redmine.teklia.com/issues/10642

Requires #1971 (closed)

For workers to generate IIIF 3-compatible URLs, they need to be able to tell which IIIF version to use. In ListProcessElements with with_image=True, and in StartWorkerActivity, a new image_server_version field should return the value of ImageServer.version for each element with an image.