MCC tests fail with MOM

[jedwards4b]

The MCC test runs a single executable ensemble of size 3 and compares the results to a single run. This failed in my tests of the cesm3_0_alpha02a candidate because the File
GEOM_FILE had the same name in all three instances. Using user_nl_mom_000[123] I changed this file name to be unique to each instance and that allows the model to run.