DART enhancements to st_archive

[kdraeder]

This PR fixes MOM_interface #248.

The changes have been tested in mi_250428-3-g333c329 and cesm3_0_beta03-121-g0a50f32.
The test revealed that additional fixes to config_archive.xml are needed, or maybe desirable,
but those will be proposed in a subsequent PR, after the solutions have been chosen in
MOM_interface #257.

[kdraeder]

@mnlevy1981 and @alperaltuntas is there any more information I should provide?

[alperaltuntas]

When running MOM6 test cases (e.g., SMS_D_Ld2.T62_t232.G.derecho_gnu) using the create_test command, I get the following failure, pointing to the changes in hist_file_extension for the ic (initial conditions) file.

ERROR: Failed to move file casename.mom6.ic.1976-01-01-00000_1.nc to archive
Traceback (most recent call last):
  File "/glade/work/altuntas/cesm.sandboxes/cesm3_0_alpha06f.sbx/cime/CIME/SystemTests/system_tests_common.py", line 799, in _phase_modifying_call
    function()
  File "/glade/work/altuntas/cesm.sandboxes/cesm3_0_alpha06f.sbx/cime/CIME/SystemTests/system_tests_common.py", line 786, in _st_archive_case_test
    result = self._case.test_env_archive()
             ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/glade/work/altuntas/cesm.sandboxes/cesm3_0_alpha06f.sbx/cime/CIME/case/case_st_archive.py", line 1277, in test_env_archive
    _check_disposition(testdir)
  File "/glade/work/altuntas/cesm.sandboxes/cesm3_0_alpha06f.sbx/cime/CIME/case/case_st_archive.py", line 1319, in _check_disposition
    expect(False, "Failed to move file {} to archive".format(_file))
  File "/glade/work/altuntas/cesm.sandboxes/cesm3_0_alpha06f.sbx/cime/CIME/utils.py", line 176, in expect
    raise exc_type(msg)
CIME.utils.CIMEError: ERROR: Failed to move file casename.mom6.ic.1976-01-01-00000_1.nc to archive

[kdraeder]

@alperaltuntas I found the same thing and suggested a fix in #257.
I separated those changes from these based on whether they were strictly related to DART.

[mnlevy1981]

I'm a little confused about the discussion on the IC files -- we noticed an issue with archiving IC files in #253 (see #253 (comment)) and I thought the decision was that we'd skip trying to archive _1 and _2 until we could make sure all the ic files were also copied to the baseline directory as well. But it seems like @alperaltuntas ran into an issue because the test suite was looking for the _1 file?