[FEATURE] Add support for user services (started controlled by specific user, not root)

[Alexey Murz Korepov]

Will be good to have ability to create and manage systemd per-user services, to allow users start-stop them. Here https://wiki.archlinux.org/index.php/systemd/User is some documentation about this.

This can be implemented via moving the .service file to ~/.config/systemd/user/ folder, and control the service status via using systemctl --user started from user credentials.

[Ewout van Mansom]

Crucial for rootless Podman as example.