Merge pull request #4502 from ESMCI/fix_bless_test_results

Fix bless test results

Fixes requiring --*-only flag
Fixes logic for default behavior of performing all bless types or only a single type
Adds exclude feature

Test suite: pytest -vvv CIME/tests/test_unit_*
Test baseline: n/a
Test namelist changes: n/a
Test status: n/a

Fixes n/a
User interface changes?:
Update gh-pages html (Y/N)?:

CIME/Tools/bless_test_results

@@ -90,6 +90,8 @@ OR
         "\ncan follow either the config_pes.xml or the env_mach_pes.xml format.",
     )
 
+    parser.add_argument("--exclude", nargs="*", help="Exclude tests")
+
     parser.add_argument(
         "bless_tests",
         nargs="*",
@@ -104,7 +106,7 @@ OR
 def create_bless_options(parser):
     bless_group = parser.add_argument_group("Bless options")
 
-    mutual_bless_group = bless_group.add_mutually_exclusive_group(required=True)
+    mutual_bless_group = bless_group.add_mutually_exclusive_group()
 
     mutual_bless_group.add_argument(
         "-n", "--namelists-only", action="store_true", help="Only analyze namelists."