Updates to CO2(avg) and CO2(diff) plots

[dcrisp-jpl]

1. For the CO2(avg) maps, when a bounding box is defined, can we plot out the baseline CO2 as well as the 2020 results?
2. For the CO2 (Diff) maps, can we enable the bounding box to create a plot of XCO2 difference for January 2020 to present? It currently allows us to create a bounding box, but then just says “There are no layers with time date enabled”.