Consider switching to ReadBuf API once stable

[Thomasdezeeuw]

Instead of accepting &mut [MaybeUninit<u8>] in read/recv calls.

Tracking issue: rust-lang/rust#78485.

[Thomasdezeeuw]

Still not stable, so closing this.

[Darksonn]

You might want to call the methods _raw or similar to make space in the API for adding this in the future.

(Ignore me if you already do this.)

[Thomasdezeeuw]

I don't really want to do that for API such as recv_from_vectored: https://docs.rs/socket2/latest/socket2/struct.Socket.html#method.recv_from, which already has like 4 variants (6 if you count peeking), I don't want to double that. Though we should probably redesign that entire method to be honest.