Add support for routing through SOCKS proxies

[m41t]

Is there a recommended way for routing iamb client's connection through tor socks5 proxy?

[VAWVAW]

According to https://docs.rs/reqwest/latest/reqwest/#proxies, we could just enable the socks feature of reqwest. The only question is whether we should add a config option or just rely on the users setting all_proxy.

[KaraZajac]

Hello! I have added a PR to help fix this issue (#575). I wanted to use iamb, but I also needed to use a proxy. The fix works on my macOS machine and lets me connect to my Matrix server (which runs on a Tor .onion service). I hope it helps! I did have AI help me write it. But I manually updated the code to conform to the project's overall style.

Thank you. :)