Move our testing from POP masks to MOM masks (mt233)

In CESM2.0/CESM2.1/CESM2.2 series POP was the default ocean model. In CESM3, POP is going to be removed and MOM will be the ocean model that's used. The masks used in our testing have been POP masks (gx1v7 and gx3v7 for example). But, as part of CESM going to use MOM, we need to update our testing (and list of scientifically supported compsets) to use MOM ocean masks rather than POP. MOM does NOT have a low resolution grid (and they are removing the t061 grid), so we will use t232 for ALL grids (now the updated t233 grid)