Get lookup typeahead results

Note: The path is a placeholder. The actual path is determined by the configuration of the app component.

Gets typeahead results to render as a dropdown list in the resource lookup input field.

When the user types into the lookup input field, Asana will send a request containing the entered string to the application's typeahead_url. The list of TypeaheadItems in the response will then be rendered in a dropdown list. When the user selects an item from the list, Asana will send a resource attach request to the app server, then process the response and render the attached resource in the widget.