tezos-client should follow HTTP redirects

In !5180 (merged), we extended the proxy server to respond to unsupported RPCs by redirecting clients to the appropriate endpoint on the node. This works already for HTTP clients that know how to follow redirects (e.g. curl -L), but not tezos-client, which we will have to extend to support following redirect responses correctly.

This feature can be implemented in the way outlined in the Cohttp docs here.