Allow nonhydrostatic version of FV3

### What is the feature/what would you like to discuss?

Allow FV3 to be run using its nonhydrostatic solver, instead of the default hydrostatic one. As the vertical velocity is now a prognostic variable, this requires the initialisation of a nonzero initial w field.

Part of this enhancement would require modifications to the src/dynamics/fv3/dyn_comp.F90 file that is located in the CAM_FV3_interface github repository.

### Is there anyone in particular you want to be part of this conversation?

_No response_

### Will this change (regression test) answers?

No

### Will you be implementing this enhancement yourself?

Yes