OZP-56: Migrate accordion layouts.

1. Cleaned up accordion dashboard's configuration in serverConfig.js.
2. Set jquery ui's sortable to not scroll on drag for accordion.
3. Fixed bug in updateSize of accordion where widget borders weren't accounted for.
4. Removed scrollbars entirely from accordion.
5. Added two tests for accordion's updateSize to ensure widget heights are calculated and applied properly with collapsed and expanded widgets.