Add CMD customization for services created from a Docker image

[FallenChromium]

Thanks for the great self-hosting experience, it's been a game changer! ❤️

For some images that I host I have to provide some CMD arguments, and it's pretty inconvenient to customize now now since using a Compose for this robs me of Traefik reverse proxy (I have to do it myself but I'd rather rely on Coolify for the labels), and currently there's no field for this in the UI for services made from a Docker image.