Reduce stalled requests due to number of requests to the same domain

[heypoom]

Shoppy requests are very slow due to a browser limitation on the number of requests to the same domain. As a result, we have these stalled requests. We tried to do exactly the same requests using Jmeter, and no issues like this. Other configurations such as caching, instance size, etc, doesn't work.

One hypothesis that we can try is to eliminate preflight requests, it should reduce the overall query time. To do this, we need to proxy all shoppy.hosted.staging.metabase.com requests via https://metabase-shoppy.vercel.app/

The goal is to speed up Shoppy loading time.