Do not create `number_eddies.csv` in `eddy_graph`

Do not create file `number_eddies.csv` in program `eddy_graph`. Since
there are no interpolated eddies any longer, the file
`number_eddies.csv` just contained the same information that is in
`ishape_last.txt` in the input SHPC. Remove argument
`unit_number_eddies` of procedure `dispatch_snapshot`.