Initialize zoom level of view type visualization to fit the entire diagram

Currently, the zoom level is left at 100% upon (re-)generation of view type visualizations and can be changed manually. It would be useful to adapt the zoom level to fit the entire diagram when a new visualization is shown, e.g., when selecting a different query in the `selected` mode.

One open question is what to do with a manually changed zoom level when showing a new view type visualization.