Output data for an expander.

This template outputs an HTML div element with the class attribute set to "yelp-data yelp-data-ui-expander". All yelp-data elements are hidden by the CSS. The div contains information about text directionality, the default expanded state, and optionally additional titles for the expanded and collapsed states.

The expander information is only output if the expander parameter is true. This parameter can be calculated automatically, but it will give false negatives for blocks that produce automatic titles.