Continued Visualization Refactoring

- onClick events are now handled globally on the WORLD-panel
(significant boost in performance of the visualization)
- clicked (active) hosts are now more clearly visualized
- removed default host visualization for the sake of full customization.
However, we will provide a simple "showHosts" configuration option for
basic underlay visualization stuff in a later version of the
VisualizationTopologyView
- removed outdated and no longer used Components