Research and report back: Using manifests from other remote sources to display images

Documentation on this: https://github.com/projectblacklight/spotlight/wiki/Resource-Scenarios

I believe this is the desired functionality:

• When I initially added a iiif url in my dev environment I got a certificate error, but I think it's because I was using a manifest from staging.
• When I added a iiif manifest from Villanova to my local spotlight instance, it sort of worked. But when viewing the items, it would not page through the images. Example here: https://spotlight-staging.galib.uga.edu/spotlight/image-protect-testing/catalog/5b698e9d334c1c9eac1806f9e3f0d447
• I tried the same thing in my Spotlight 3 local instance, thinking that perhaps this is fixed in the latest version, and it seemed to load the manifest URL, but then the item(s) never showed up in the item list.