[FEATURE] Visualize other components of the grid

[Thijss]

Would it be nice to also visualize other arrays of the grid? These could be represented as separate graph-nodes.

I am thinking of:

• sensor arrays
• load arrays

For instance, we could connect a load-graphnode to each node
We should make this optional, since it will clutter the UI.

[jaapschoutenalliander]

We are also missing ThreeWindingTransformers, which I think is the most ipmortant to add

[jaapschoutenalliander]

I created a very simple implementation for three-winding-transformers: #68

[petersalemink95]

During the meet-up the following components were also requested: asym line + generic branch. Might be good to think about how we can visualize all PGM components