Add possibility to "proxy" S3 and not expose the S3 URL

[ipf]

I'd like to use the S3 driver in a way, that the backend S3 URL is not exposed to the public and can be transparently used in TYPO3.

To make it more clear:

Currently I'm storing things in the backend, and the frontend uses some URL like "https://s3compat.storage.example.com/...."
I'd rather like to be able to use it like "https://my-typo3-site.com/[nameofthestorage_or_whatever/fileadmin/..." that streams the files from the S3 backend to the frontend without exposing the S3.