Delete socat dependency on sci

[schaefi]

Description

sci is a static compiled binary to be used with any rootfs. When using an app registration for firecracker in resume mode, sci calls socat in VSOCK-CONNECT mode to establish a connection. That socat creates a dependency to socat in the guest. We could prevent that by adding an implementation based on:

• https://docs.rs/vsock/latest/vsock/struct.VsockStream.html#method.connect_with_cid_port
• https://docs.rs/pty/latest/pty/

To run the command in the same way socat does it

Acceptance Criteria

• guestvmtools sci no longer requires socat