Socket support

[arihant2math]

TODOs:

• Fix syscall errors (too many incorrect EINVAL returns right now)
• Find the right crate for TCP/UDP (smoltcp vs embassy-net)
• recv/recvmsg/send/sendmsg implementation.
• Get rust unix socket API working.

Future TODOs:

• AF_BLUETOOTH support
• ICMP support (for ping)

Initial PR: #127

[arihant2math]

The problem I'm seeing here is the rest of the I/O will be async, but this portion would be sync. I feel like this would lead to some conflicts later down the line. We might be able to circumvent this by implementing the socket layer ourselves.

[arihant2math]

Nevermind, seems like https://crates.io/crates/embassy-net is an async implementation.