CDAT Migration - Update regression testing notebook for `lat_lon` set using run script

[tomvothecoder]

Is your feature request related to a problem?

The current regression testing notebook compares the results of ex1.py, which tests a limited subset of variables.

Describe the solution you'd like

• [ ] Execute the run script using the lat_lon, lat_lon_land, and lat_lon_river sets
• [x] Add regression testing notebooks for .json and .nc
• [ ] Debug issues if needed

Describe alternatives you've considered

No response

Additional context

No response

[tomvothecoder]

Closed by #794