[FEATURE] Islandora IIIF: Allow for relative file paths in IIIF manifests

[alxp]

Overview of feature request

What kind of user is the feature intended for?
Systems administrator

What inspired the request?
When testing the Drupal 10 compatibility of Islandora Mirador, I set up a simple local stack with an instance of Cantaloupe 5.0 running on my local computer.

Since it was local, I configured it to serve files directly from the Drupal sites/default/files folder rather than making web requests.

This would be a useful feature for performance improvement for installs where Cantaloupe can run on the same machine as Drupal.

What existing behavior do you want changed?

Add a config setting to let the site owner choose to have the IIIF Manifest include relative paths.

Follow this setting when generating IIIF manifests.

Any brand new behavior do you want to add to Islandora?

Any related open or closed issues to this feature request?

[rosiel]

Is there any documentation needed for this? For example, does Cantaloupe need to be configured to know where paths are relative to (the drupal root directory, perhaps?)

[alxp]

@rosiel If/when we decide to separate out Islandora IIIF from Islandora then it would make sense to have a section in the README on setting up a basic Cantaloupe install.