Design and implement model output

[HendrikTolman-NOAA]

The basic calling structure for model output has been put in place in PR #19, Issue #30. This issue is intended to build model output up to and including a full data flow. The first five sub-issues deal with the present output options of WW4. Each of these issues starts with the question if we want to retain this output option for WW4

• Address field output (Issue Field output #44).
• Address point output (Issue Point output #45).
• Address track output (Issue Track output #46).
• Address restart file output (Issue Restart files #47).
• Address boundary conditions output (Issue Boundary Conditions #48).
• Is there any new output that we would like to consider for WW4 (Issue Need for new output #49).