Allow CORS

[michaelheider]

Would be cool if there was a setting to allow CORS.

Either an option to not block OPTION requests, or better: CORS headers directly from within the plugin.

The issue I'm facing:
I want the frontend to be accessible, as it doubles as homepage. But the backend should be GeoBlocked. For UX, the frontend makes a test request to the backend (which should fail with the HTTP status code configured in GeoBlock), however, due to how the backend is set up, this requires CORS (for the successful requests). The preflight/OPTION request always fails as it is blocked, leaving the frontend in the dark as to what exactly is happening.

Workaround:
Reconfigure backend to allow a test request without CORS-enforcing headers.