feat(proxy): Add socks4a proxy protocol support

[0x676e67]

This pull request includes several updates to the Cargo.toml file and enhancements to the SOCKS proxy support in the src/connect.rs and src/proxy.rs files. The most important changes include the addition of new dependencies, the introduction of remote_dns support for SOCKS4 proxies, and the refactoring of related code to accommodate these enhancements.

SOCKS Proxy Enhancements:

• Updated ProxyScheme::Socks4 to include a remote_dns boolean field.
• Introduced the socks4a variant in ProxyScheme to support DNS resolution via the proxy.
• Updated the connect_socks method in ConnectorService to handle the remote_dns field for SOCKS4 proxies.
• Modified the socks module to accommodate the remote_dns field in ProxyScheme::Socks4.
• Updated the fmt::Debug implementation for ProxyScheme to reflect the remote_dns field in SOCKS4 proxies.