When running with MARBL tracers, want oxygen in h.bgc.native stream (even when interpolating all the other variables)

This will probably require an update to

```py3
if vert_grid in ["native", "both"]:
self._diag_table_dict[f"{freq}_native_z"]["fields"][
'$OCN_DIAG_MODE != "none"'
]["lists"][0].append(varname)
```

in [`MARBL_diags_to_diag_table.py`](https://github.com/ESCOMP/MOM_interface/blob/main/cime_config/MARBL_scripts/MARBL_diags_to_diag_table.py), adding a check for whether `varname` is in a list of fields always added to the native stream. I think this is all it will take, as the `combine_medium_native_z()` function will combine `medium` [2D] and `medium_native_z` [3D with native vertical] correctly, including `h` and `volcello` because of the presence of 3D fields