Init boundary exchange test

[mwaxmonsky]

Description
Adds unit tests that setup and verify the boundary exchange for a simple example of the double gyre bathyT field during initialization.
Also updates the current TIM infrastructure to enable building and running these under MPI and modularizes the common helper library and shared main test runner.

Fixes #

How Has This Been Tested?
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Checklist:

• 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
• New check tests, if applicable, are included
• make distcheck passes