Add compression

[sverhoeven]

The response of get_value can be big. It would be nice if response could be compressed with gzip or brotli so it is smaller over the wire.
Both client and server implementations should have gzip support and maybe brotli support.

[sverhoeven]

Check compression support

• python client, httpx, https://www.python-httpx.org/quickstart/#binary-response-content
• python server, connexion, https://connexion.readthedocs.io/en/latest/middleware.html#list-of-useful-middleware
• julia serve, http, not found, but does support middleware so could roll our own
• R fiery http server