[CDN] Simplify CDN authentication for interacting with its REST API
Unless I'm missing something, right now to work with a CDN API one needs to go through AD and setup users/rules for every CDN endpoint you may have for all your sites. Then on CMS side for each site + CDN first authenticate yourself, then get a token to interact with the API. Once all that is done, each site must also know the subscriptionID, resourceGroup, profileName, endpointName just to access the CDN's API.
The actual endpoints for working with the CDN is great, it's just authenticating and ensuring you're interacting with the correct CDN that is very involved. So this makes it very difficult to purge content on CMS updates compared to other CDN services that allow you to create API tokens for interactions, such as Cloudflare https://api.cloudflare.com/#getting-started-requests.
Add ability to create tokens that you can revoke to interact with specific CDNs via REST API.