Includes a tag containing a URI that is connected with a fullscreen
display of a coplet. If fullscreen is explicitly unsupported, no tag
will be created. Otherwise, it depends on the current layout being the
fullscreen layout or not whether the URI contains an event that switches
to this layout or not.
Example XML:
<fullscreen-uri>fullscreen-event-if-supported</fullscreen-uri>
<!-- output from following renderers -->