Store asset transformations for reference when serving assets from outside of the studio app

Summary When not using the Directus Studio app to serve assets, there is currently no way to track asset transformations through the API or through Directus system collections. We deliver our assets through our own CDN. We currently use Directus Studio app as our asset management system, where Directus stores all the assets on our own S3 bucket. We then use Akamai to serve those assets on our sites through a custom URL. This limits our ability to use asset transformations in a programatic way when serving our assets. Currently the only way to see these transformations is S3. Here is any example Basic Example _No response_ Motivation Be able to use Directus Studio app features when using an external CDN provider to serve assets managed in Directus. Detailed Design Alter directus_files • Altering directus_files to include new fields to track asset transformations and the properties used to transform them • Potentially a field named asset_transformation_fi…