Utility function that launches the default application registered to handle the specified uri.
Synchronous I/O is done on the uri to detect the type of the file if required.
The D-Bus–activated applications don't have to be started if your application terminates too soon after this function. To prevent this, use launch_default_for_uri_async instead.
the uri to show
an optional AppLaunchContext
true on success, false on error.