NEON sites csv file generation and maintenance

Simulation at NEON sites uses a [wrapper script](https://github.com/ESCOMP/CTSM/blob/master/tools/site_and_regional/neon_surf_wrapper.py) to subset data, download neon data and update the surface data based on that NEON data. This wrapper script uses a [NEON specific csv file](https://github.com/ESCOMP/CTSM/blob/master/tools/site_and_regional/neon_sites_dompft.csv) with information on site name, domain, lat, lon, dominant pft, and years of data.

This NEON csv file should be create programmatically so that it is reproducible and bugs are caught more easily. If this already exists, a link needs to be provided or maintained in the NCAR_NEON repo. The designation of dominant pft should have documentation to identify the method by which this pft is set.

definition of done: script to generate the NEON csv file in the NCAR-NEON repo

Highlighting here https://github.com/ESCOMP/CTSM/issues/1934 which will use NEON inventory data to determine percentage of PFT in the surface data files and [#PR1932](https://github.com/ESCOMP/CTSM/pull/1932) for further discussion and figures by @adrifoster on the mixture of species at a set of NEON sites.