Function render_list_output 

pub fn render_list_output(
    title: &ListTitle,
    registry: &[RegistryEntry],
    canister: Option<&str>,
    role_kinds: &BTreeMap<String, String>,
    readiness: &BTreeMap<String, ReadyStatus>,
) -> Result<String, ListCommandError>

Render a named list view with a fleet/source title above the registry table.