Displaying map data points in units of AQI

[exchrotek]

NO LONGER NEEDED

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As a West Oakland resident, I'd like to see the map data in units and values that are familiar and follow standard convention so that my understanding and interpretation of the data is intuitive.

Acceptance Criteria:

• Units being displayed are in AQI

Background:
Right now the data on the map is being reported in values of mass concentration for PM2.5. It's safe to assume people don't grasp what micrograms per cubic meter of PM2.5 really means. AQI is a much more familiar unit to the public.

Info used to generate trendlines between PM 2.5 conc and AQI:
https://docs.google.com/spreadsheets/d/11kdXzr9eFBc9CaH3LY-6iT60qgphA_GzcFEWCWVNWNA/edit#gid=0

[exchrotek]

Useful link for post-mvp activities as we begin to incorporate both spatial and temporal averaging of PM 2.5 data:
https://www.airnow.gov/sites/default/files/2020-05/aqi-technical-assistance-document-sept2018.pdf

[exchrotek]

NO LONGER NEEDED.

Refer to #464