fms2_io: Add generalized indices test

[J-Lentz]

Description
Adds a test to ensure that fms2_io is able to write and read back a domain-decomposed array where the x and y dimensions correspond to arbitrary permutations of the array's first three indices.

How Has This Been Tested?
Test builds and passes on C5 using intel-classic/2023.2.0.

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

[uramirez8707]

Thank you for this update! This will very helpful as we make changes to fms2io (i.e the mpp_gather updates)!