fix climate zone calculation

[hdunham]

Currently, instead of determining the climate zone of the user-provided lat/long, we determine the closest representative city and use its climate zone. This can lead to an incorrect zone being used. To fix this, we would want to do something similar to how we determine the AVERT region and would need new shape files that represent the zones not just the cities.

[zolanaj]

Was this addressed in the Cambium update here? Can we close?

[zolanaj]

tagging @adfarth