Performs case-insensitive string comparison and returns: 0 if two strings are equivalent, 1 if the first string is greater than the second, and -1 if the first string is less than the second.
https://www.mongodb.com/docs/manual/reference/operator/aggregation/strcasecmp/#mongodb-expression-exp.-strcasecmp
Performs case-insensitive string comparison and returns: 0 if two strings are equivalent, 1 if the first string is greater than the second, and -1 if the first string is less than the second.