It should be easier to use Cloudinary as a storage option for ActiveStorage

[jagthedrummer]

Currently we use the presence of CLOUDINARY_URL to determine whether images should use ActiveStorage or the Cloudinary JS widget for uploads. In a vanilla Rails app it's possible to setup Cloudinary to be the back end storage option for ActiveStorage. One reason you might want to do this is that provisioning the Cloudinary add-on is easier than provisioning an S3 bucket and getting all of the settings just right (IAM, CORS, etc...).

We probably need a more explicit trigger so that a developer could have CLOUDINARY_URL set but still opt in to the ActiveStorage style image handling with Cloudinary as the storage location.

Ideally if we can make this work it would:

• Allow uploads to go directly to Cloudinary instead of going through the application server
• Bypass ActiveStorage analysis (maybe optionally)
• Allow use of Cloudinary image delivery/manipulation directly (via cl_image_tag and cloudinary_url) instead of relying on ActiveStorage representations