Update / Replace the ocn diag timeseries awk script budget calculations and reporting

[bertinia]

Currently the ocn diag timeseries scripts call awk scripts to look at the coupler log outputs to extract freshwater and heat budget information. This is fragile and breaks when the coupler log format changes. The information necessary for reporting budget information should be extracted directly from the coupler history output. Will work with @jtruesdal to get this functionality included in the postprocessing suite.

[bertinia]

This work will involve updating the coupler code to output fields directly to the coupler netcdf files. It will also involve cross-checks with the component models for their budget data to ensure integrity. The WG co-chairs are still debating the best way to do this budgeting and reporting.

Meanwhile, in order to make the current scripts that parse the coupler log output more robust and maintainable, they will be rewritten in python.