We were accidentally setting the createMeeting query parameter when
creating a widget through Dimension's UI, which tells the widget to use
the non-UI method of connecting to a meeting.
This adds the widget and the configuration for it to the integration
manager, so that the user can add a BBB widget. The code that will
actually run inside of the widget is not yet here.
A few CSS things are updated as well to make them more generic, as
we reused a few things that were previously jitsi only.
