Fix projection in area plots

[JustinElms]

Background

We were notified of an issue that prevented area plots below -30 degrees latitude. After some digging I found that the Lambert Conformal projection used in the area plotter for areas within (-85, 85) deg latitude does not extend beyond this range. Switching to the Mercator projection allows all plots within this range. While testing I also found that the area boundary is not properly calculated for polar plots outside of this range, especially when the area intersected the north/south pole. To resolve this I opted to re-calculate the bounds and centroid in the plots own CRS to ensure that the plot was centered on the polygon.

Why did you take this approach?

Adopting the Mercator projection allows us to use the majority of the globe for standard plots.

Screenshot(s)

Comparisons of plots before/after changes:

Checks

• I ran unit tests.
• I've tested the relevant changes from a user POV.
• I've formatted my Python code using black ..

Hint To run all python unit tests run the following command from the root repository directory:

bash run_python_tests.sh