In order to solve #87642, we need to proxy any images in the media area via the public API.

This solves two main cases:
1) Where the primary redirect is not yet pointed to us via DNS
2) Where a service like Cloudflare is in front of the primary redirect, and blocks "hotlinking" images

These cases both used to work fine, as media was served from *.files.wordpress.com regardless of the actual
domain being used.  Once this was been moved to use wp-content/uploads (in order to fix issues when third
party cookies are blocked), the two cases above (and probably some others we don't know about) stopped working.