Incorporation of NHD Waterbodies

Incorporated NHDPlus waterbodies -Added data paths for waterbody RDS and POIs to json -Added function for calculating median waterbody width to NHDNavigate functions. This runs really slow for the entire CONUS (440K+ waterbodies and should be made more efficient with parallel or some other option). -Added NHDwaterbody conversion from shapefile to RDS within 'getData' -Added POI (inlet/outlet) identification in 'NHDNavigate'. No size filter/criteria applied to waterbodies yet. If a flowline had a populated WBAreaCOMID, it delineated with inlet/outlet POIs. We can decide on this later.