Add three new CVMix parameters

[mnlevy1981]

CVMix moved three hard-coded fortran parameters to user-defined parameters than can be set via cvmix_init_kpp(). This PR allows users to set those three parameters via MOM_input / MOM_override, but the MOM6 default values match the CVMix default values (which match the previously-hardcoded values)

Note that this requires the code in CVMix/CVMix-src#109 to build / run; I will accept that PR, push it to https://github.com/mom-ocean/CVMix-src, and update the external in this PR once testing is complete.

Testing: I am running pr_mom; one test has already completed and it is bit-for-bit (as expected). I will add a comment when the rest of the test suite finishes.

[mnlevy1981]

The pr_mom tests all pass (run successfully, and are bit-for-bit with head of dev/ncar):

71	PASS
	5	RUN (PASS)
      1 DIMCSL_Ld1.TL319_t232.G_JRA.derecho_intel.mom-cfc_mods
      1 ERI.TL319_t232.G_JRA.derecho_intel.mom-debug
      1 ERS.TL319_t232_wg37.GW_JRA.derecho_intel
      1 SMS_D.TL319_t232.G_JRA_RYF.derecho_intel
      1 SMS_Ld2.ne30pg3_t232.B1850C_LTso.derecho_intel
	5	BASELINE (PASS)
      1 DIMCSL_Ld1.TL319_t232.G_JRA.derecho_intel.mom-cfc_mods
      1 ERI.TL319_t232.G_JRA.derecho_intel.mom-debug
      1 ERS.TL319_t232_wg37.GW_JRA.derecho_intel
      1 SMS_D.TL319_t232.G_JRA_RYF.derecho_intel
      1 SMS_Ld2.ne30pg3_t232.B1850C_LTso.derecho_intel
0	BFAIL
0	CFAIL
0	SFAIL
0	FAIL

The github actions tests should pass once I update the CVMix submodule, which I will do after @gustavo-marques and I review both this PR and the one in CVMix.

[mnlevy1981]

Assuming the CI tests all pass, this is ready to be merged