A negative value if a is before b, a positive value if a is after b, or 0 if they are the same
VALID_NUM_TYPES order:
decimallatin_lettermonth_nameday_of_weekgreek_lettergreek_letter_english_nameromanchinese_wordschinese_financialchinese_heavenly_stemchinese_earthly_branchchinese_solar_termcyrillic_letterhebrew_letterbinaryoctalhexadecimalarabicenglish_cardinalenglish_wordsfrench_wordsastrological_signnato_phonetic
Compare two num types based on their order in the VALID_NUM_TYPES array