[Feat] SSH Server opt-in

[DarkGhostHunter]

This PR adds an SSH Server to the DevContainer (opt-in), with the purpose of letting the developer connect remotely on situations where he doesn't have a mature DevContainer provisioner or just needs a remote connection from elsewhere.

The developer only needs to uncomment the port and set a password.

services:
    laravel.test:
        ports:
            # - '${SSH_PORT:-2222}:22'
        environment:
            # SSH_PASSWORD: 

Note

If the password is empty, the user won't be able to log in.

This is done installing OpenSSH, and starting an SSH Server along PHP through Supervisor.

The DevContainer provisioner has no obligation to serve an SSH Server via network. For example, DevPod uses stdio, while others may use file sockets or expose the Docker Machine to the network (overkill for a single proyect), hence why this patch.