Plots near paris are not centered correctly

[pfaion]

I found out that in paris the bounding box will be very stretched and not square.
Rendering does not render centrally though in this case, but left-justified.
I assume that close to the poles the bounding box also does not make much sense.... this needs to be tested.

• Check behavior for poles.
• Find a better way of mapping a center and area size to an overpass bounding box, check pyproj.
• Add a unit-test to ensure resulting bbox is roughly square or rendered center is close to bounding box center.
• Make sure rendered square is centered in actual bounding box.