GeoPlot - Adding plotting information via a configuration file.

[SamuelHall700]

Currently GeoPlot contains all it's plotting information in internal config files <GeoPlot/bas_geoplot/config/interactive.json> and <GeoPlot/bas_geoplot/config/static.json> which contain default plotting methods of a collection of data-types commonly used in mesh contruction (Fuel, tCO2e, Max Speed, SIC etc.). These values are currently not able to be extended or altered without updates to the GeoPlot repository.

GeoPlot should be extended to allow for the use of a configuration file for plotting information, which super-seeds the internal config file (though the default internal config file is used for any values not specified in the external config file). This would allow for plotting of new data-types or changing existing plotting of current data-types without needed to update the GeoPlot repository.

This should be accessible via the CLI.
plot_mesh <env_mesh.json> <plotting_config.json>

where the <plotting_config.json> file is of the form (or similar):
{ "SIC": { "fill_color": { "colormap": "BuPu_06", "cmin": 0.0, "cmax": 100.00 } }, "Temperature": { "fill_color": { "colormap": "Veridis" } } }

With the plotting information for SIC given in the config overwriting internal "SIC" plotting information, and plotting information for "Temperature" being added as it is not included in the default internal config file.