Port delp_total diagnostic to public version of SHiELD

[spencerkclark]

Description

This PR adds a diagnostic for the pressure thickness which includes the mass of water condensates (delp_total). This is the actual pressure thickness used internally by the dynamical core to define things like tracer mixing ratios, and so it is useful to be able to output it for diagnosing budgets. In many ways it is a simpler diagnostic to implement than the existing delp diagnostic.

xref: I implemented this diagnostic as part of another merge request to the internal version of SHiELD (see this commit; note authentication is needed to access the link).

Since this is such a simple change, and one that already exists in the internal version of SHiELD, I hope we can review / merge it quickly, as I need it for a new simulation. Thanks!

cc: @lharris4 and @bensonr

How Has This Been Tested?

I tested this in a short C12 resolution simulation within a Docker container, and validated that I could reproduce the existing delp diagnostic using this new delp_total diagnostic and the sum of the condensate tracers (notebook).

Checklist:

Please check all whether they apply or not

• My code follows the style guidelines of this project
• I have performed a self-review of my own code
• I have commented my code, particularly in hard-to-understand areas
• I have made corresponding changes to the documentation
• My changes generate no new warnings
• Any dependent changes have been merged and published in downstream modules

[lharris4]

This is good, thank you. Note that if GFS_PHYS is not defined then delp_dycore and delp are identical: the version used when GFS_PHYS is defined is to match the moist mass (no condensates) used in the Legacy GFS and expected by downstream applications of the GFS.

[lharris4]

Simple is good. Thanks for making these changes.