Fix sockets

[Arshia001]

A couple of small fixes to sockets:

• Fixed endianness issue when deserializing IPv6 addresses that caused swapped bytes in each u16.
• Fixed receiving data from UDP sockets that have not been connected to a remote socket (i.e. server sockets).

[ptitSeb]

This seems very similar to #4166

[theduke]

LGTM, but it would be lovely if we had asnapshot tests for this...

EG: a simple UDP server and client that exchange a few packets , once in Rust and once in libc.

Goes a long way in preventing regressions.

[Arshia001]

@theduke the problem is that UDP is still not really working. There's something wrong with either binding or receiving, but I haven't figured out exactly what it is yet.

[theduke]

@theduke the problem is that UDP is still not really working. There's something wrong with either binding or receiving, but I haven't figured out exactly what it is yet.

Even more important to have a test then.

[Arshia001]

Absolutely, as soon as someone actually fixes it. I'm out of time for now, have to move on to other priorities, but I'll keep this on my task list for later.

[Arshia001]

@theduke CI should be green soon, just need an approval to get this merged in