function hostAction(settings, action, params = {}) {
    var request = {
        settings: settings,
        action: action,
    };
    for (var key in params) {
        request[key] = params[key];
    }

    return chrome.runtime.sendNativeMessage(appID, request);
}
Send a request to the host app

@since 3.0.0

@param object settings Live settings object
@param string action   Action to run
@param params object   Additional params to pass to the host app
@return Promise