query/set_paramfile tools: Work with CDL files

Just putting together some thoughts on this.
- Okay to call out to `ncdump` and `ncgen` for this functionality rather than doing something fully within Python
- Ensure that `ncdump` uses the right precision (`ncdump -p 9,17`): https://github.com/ESCOMP/CTSM/wiki/Moving-a-parameter-to-the-params-file
- Write a new SystemTest that does two short runs, one of which uses a paramfile that just went through `ncdump` → `ncgen` (i.e., no changes made), ensuring they're b4b identical.
- Add `--cdl` flag to both tools. `query_paramfile` means it prints as CDL format (only allow this if querying entire file. `set_paramfile` means `--input` file needs to be CDL instead of netCDF. Although maybe that could be auto-detected and then the flag would mean to SAVE to CDL. OR maybe we could have separate `--to-` and `--from-` flags.
- Only do this after #3414!