Cache-Control headers causes browser to cache incorrectly after updates

[JackLewis-digirati]

From Gary:

we have Cache-Control headers in addition to etags in iiif-presentation and it seems to be breaking browser caching (the browser isn't sending an If-None-Match)
I had to clear my browser cache to get an updated response from /collections/root?page=1&type=Manifest

WE need to stop the browser caching responses after an update to a resource - might be complicated by how the hierarchical resources live on a different URL to create/update endpoints meaning the caching isn't invalidated

NOTE: look into Content-Location headers which should cause the browser to remove items from other URL's - https://developer.mozilla.org/en-US/docs/Web/HTTP/Headers/Content-Location

alternatively, no-cache will work, with a draft implementation here - https://github.com/dlcs/iiif-presentation/pull/141/files