Jonatan Hatakeyama Zeidler

Results 2 issues of Jonatan Hatakeyama Zeidler

## What does this PR do This PR adds a SockAddrLl struct to represent a `libc::socketaddr_ll` with the additional guarantee of valid data, that can be made into a `LinkAddr`...

## What does this PR do This PR adds a `impl From for LinkAddr` to help users of nix avoid `unsafe` code. See https://github.com/nix-rust/nix/issues/2059#issuecomment-1878463448 for reference. ## Checklist: - [x]...