Make PodmanCompose.prefer_volume_over_mount configurable

[This configuration](https://github.com/containers/podman-compose/blob/main/podman_compose.py#L1675) is statically set to True. However, there are cases where `--mount` syntax is required, for example, when colons in a path would be confused with the colon separators in the shorthand syntax.

I can fix this if someone can comment on the preferred method of making this configurable.