…in new optional argument for additional control over file targeting. we also now have a \"run one file only\" style flag. new test config file fre/tests/test_files/CMORbite_var_list.json contains variables for processing test cases being workd through in run_test_file_cases.py with notes

…ariable8-grids

…e code currently relies on. unsure how useful the exact way i wrote things down is, but im hoping ot leverage it for structure and or setting up some formulaic approaches and or rules. additionally, merge multiline printstateaments into one call using legal but maybe awkward looking multiline syntax, some other readability edits too

…see how it goes...