HUC12 Load and Concentration Plots

[sjordan29]

@aufdenkampe and @caitlinlulay -

The plot function in the dynamic_plot library can now plot info like stage2/data_output/huc12_loads_gdf.parquet (and other metrics that would be calculated).

In this parquet file, there was no tp_conc column, so the define_colorbar_extremes function failed. I added a few lines that skirt around the issue here, but these will likely need to be updated to have the colorbar plot as desired once you have more information in the dataframe.