Zoom does not fit in some cases

[koraa]

When searching for some cities, the result yields no pins at all.
Try "Hannover" for instance.

When you zoom out you might see some.

[koraa]

This is likely caused by the zoom being set to a default level.

As the simplest approach to mitigate this we could use an adaptive zoom: Zoom out until we see at least 3 pins.

This requires some math to get the rectangular canvas right.

[koraa]

We should take into account, that we don't want to scroll out too far if there is only one or two stores in a city.
Use some weighting method.

[koraa]

Time needed: 7h (This will include first repairing the JS, which is broken. This will be done together with #19)

[koraa]

We also need to take into account the size of the object we're looking at/searching for.
I therefor propose a view that focuses the entire geometry in question +15%/-30% percent zoom to optimize for pins in sight.
When there is no size given, we should go with minimum zoom to see at least N pins.

[koraa]

Time needed: 10h