Manage CORS issues

[CharlesNepote]

Some features are broken due to cors issues (flag products, tests if the product exist on OBF, OPF...).

The cors proxy we were using is not working anymore: https://cors-anywhere.herokuapp.com/

We seem to have three options:

1. Install a cors proxy
2. Modify cors configuration of OFF websites
3. Modify Power User Script to manage cors issues.

1. Creating a cors proxy

This option is interesting because it allows to avoid these kinds of issues for various types of usages.
Some interesting links to investigate:

• https://www.npmjs.com/package/cors-anywhere
• https://github.com/juliankamil/docker-cors-anywhere
• https://stackoverflow.com/questions/45986631/how-to-enable-cors-in-nginx-proxy-server

3. Modifying Power User Script

Some libraries seem to manage cors issues in user scripts:

• https://github.com/jgjake2/myUserJS-API#jMod_jQuery
• https://stackoverflow.com/questions/24688294/how-do-i-allow-cross-origin-requests-from-greasemonkey-scripts-in-firefox/24690446#24690446
• https://wiki.greasespot.net/GM.xmlHttpRequest

See also: https://addons.mozilla.org/fr/firefox/addon/cors-everywhere/