Add a new `podman machine cp` subcommand to allow users to copy files or
directories between a running Podman Machine and their host.
Tests cover the following cases:
- Copy a file from the host machine to the VM
- Copy a directory from the host machine to the VM
- Copy a file from the VM to the host machine
- Copy a directory from the VM to the host machine
- Copy a file to a directory
- Copy a directory to a file
Signed-off-by: Jake Correnti <jakecorrenti+github@proton.me>