Implement user-suggested feedback

[eyvorchuk]

Charles, Kristyn, and Narges have given some suggested improvements to the tool:

• Remove on-demand suffix at the end of the output filename for downscaled data (they didn't suggest this, but I think that descriptor is unnecessary)
• Make the climate index list more readable, as currently, the indices with long names make it so that users have to scroll right to get the full description
• Enable users to draw a rectangle on the map to choose the size of the downscaling subdomains (with a maximum of 3x3 degrees)
• After a user's indices are computed, enable them to generate plots of the indices and download figures
• Add lat/lon coordinates of selected region to output filename for downscaled data with two decimal places (e.g. pr_*_coords_50.33,-117.34.nc)
• Add metadata information to output filenames for computed indices (e.g. for cooling degree days -> cdd_CMIP6_BCCAQv2_IPSL-CM6A-LR_ssp245_1950-2010_se-bc_coords_50.33,-117.34.nc)