fix(host): differentiate no config and config error

[brooksmtownsend]

Feature or Problem

This PR updates the handling of the get_config control interface function to return a None when a configuration isn't found, instead of an error making it difficult to tell if the configuration was absent or if there was a legitimate error.

Related Issues

Fixes #1906

Release Information

Consumer Impact

Testing

Unit Test(s)

Acceptance or Integration

Manual Verification

[thomastaylor312]

This code is good to go, but we should also include an update to the get_config function in the ctl client

[brooksmtownsend]

@thomastaylor312 I did test with the current wash and it looks like it works well, for context the code:

    let config_response = ctl_client
        .get_config(name)
        .await
        .map_err(suggest_run_host_error)?;

    sp.finish_and_clear();

    if !config_response.message.is_empty() && !config_response.success {
        error!("Error getting configuration: {}", config_response.message);
    };

    if let Some(config) = config_response.response {
        Ok(CommandOutput::new(
            format!("{:?}", config),
            config.into_iter().map(|(k, v)| (k, json!(v))).collect(),
        ))
    } else {
        Err(anyhow::anyhow!("No configuration found for name: {}", name))
    }

Perhaps we could update the doc comment to better indicate return values?

[thomastaylor312]

Yeah, figured it worked fine, but was just more concerned about the API. I think a comment would be fine