Implement native function of levenshtein(80)

[guixiaowen]

Description

Convert Spark's built-in function levenshtein to execute as a native function.

Spark function name:
levenshtein

Method description:

levenshtein(str1, str2[, threshold]) - Returns the Levenshtein distance between the two given strings. If threshold is set and distance more than it, return -1.

Examples:

SELECT levenshtein('kitten', 'sitting');
3
SELECT levenshtein('kitten', 'sitting', 2);
-1

To Native function

f::string::levenshtein