Support Interval Unit Abbreviations in Interval Literals

"year" | "years" | "y" | "yr" | "yrs" => YEAR
"month" | "months" | "mon" | "mons" => MONTH
"week" | "weeks" | "w" => WEEK
"day" | "days" | "d" => DAY
"hour" | "hours" | "h" | "hr" | "hrs" => HOUR
"minute" | "minutes" | "m" | "min" | "mins" => MINUTE
"second" | "seconds" | "s" | "sec" | "secs" => SECOND
"millisecond" | "milliseconds" | "ms" | "msec" | "msecs" | "mseconds" => MILLISECOND
"microsecond" | "microseconds" | "us" | "usec" | "usecs" | "useconds" => MICROSECOND