Try to merge MPI and serial drivers by adding MPI calls to serial driver

[Whyborn]

CABLE

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Description

Try to bring the MPI and serial drivers into parity, by adding the MPI bits to the serial driver, rather than trying to re-arrange the the MPI drivers.

Type of change

• code clean up

Checklist

• The new content is accessible and located in the appropriate section
• I have checked that links are valid and point to the intended content
• I have checked my code/text and corrected any misspellings

Testing

• Are the changes bitwise-compatible with the main branch? If working on an optional feature, are the results bitwise-compatible when this feature is off? If yes, copy benchcab output showing successful completion of the bitwise compatibility tests or equivalent results below this line.

• Are the changes non bitwise-compatible with the main branch because of a bug fix or a feature being newly implemented or improved? If yes, add the link to the modelevaluation.org analysis versus the main branch or equivalent results below this line.

Please add a reviewer when ready for review.

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📚 Documentation preview 📚: https://cable--658.org.readthedocs.build/en/658/

[Whyborn]

MPI things done on the master, that are not done in serial:

These things are done once, in a if (CALL1) block:

• Broadcasting the size of the timestep dels, line 459
• Create the land decomposition, lines 462-465
• Allocate arrays for send/receive status, lines 470-473
• Duplicate the mpi communicator for input and output MPI calls, lines 474-475
• Distribute the biogeophysics, climate, CASA and POP parameters to the workers, lines 482, 487, 498, 501
• Copy master meteorology and vegetation input data (read into met and veg) to the master versions (imet and iveg), to be distributed, lines 505-577
• Create send and receive types for the input and output, lines 583, 587, 593, 597, 600, 607, 616, 624

The remaining things are done more than once:

• Broadcasting the number of steps in the year kend, line 395.
• Sending of input to workers, lines 694, 699
• If CASA-CNP, receiving of timestep info, lines 773, 780, 787
• If CASA-CNP, sending of timestep info, line 792
• If start of day, send CASA dump timestep, line 819