MCOL-785 Implement DISTRIBUTED JSON functions

The following functions are created:
Create function JSON_VALID and test cases
Create function JSON_DEPTH and test cases
Create function JSON_LENGTH and test cases
Create function JSON_EQUALS and test cases
Create function JSON_NORMALIZE and test cases
Create function JSON_TYPE and test cases
Create function JSON_OBJECT and test cases
Create function JSON_ARRAY and test cases
Create function JSON_KEYS and test cases
Create function JSON_EXISTS and test cases
Create function JSON_QUOTE/JSON_UNQUOTE and test cases
Create function JSON_COMPACT/DETAILED/LOOSE and test cases
Create function JSON_MERGE and test cases
Create function JSON_MERGE_PATCH and test cases
Create function JSON_VALUE and test cases
Create function JSON_QUERY and test cases
Create function JSON_CONTAINS and test cases
Create function JSON_ARRAY_APPEND and test cases
Create function JSON_ARRAY_INSERT and test cases
Create function JSON_INSERT/REPLACE/SET and test cases
Create function JSON_REMOVE and test cases
Create function JSON_CONTAINS_PATH and test cases
Create function JSON_OVERLAPS and test cases
Create function JSON_EXTRACT and test cases
Create function JSON_SEARCH and test cases

Note:
Some functions output differs from MDB because session variables that affects functions output,e.g JSON_QUOTE/JSON_UNQUOTE
This depends on MCOL-5212

mysql-test/columnstore/basic/t/func_json_valid.test

@@ -0,0 +1,195 @@
+--source ../include/have_columnstore.inc
+--disable_warnings
+DROP DATABASE IF EXISTS json_valid_db;
+
+--enable_warnings
+CREATE DATABASE json_valid_db;
+
+USE json_valid_db;
+
+--echo # ----------------------------------------------------------------------
+--echo # Test of JSON_VALID function.
+--echo # ----------------------------------------------------------------------
+--echo #
+--echo # String literal - valid JSON
+--echo #
+
+CREATE TABLE t1(l LONGTEXT) ENGINE = COLUMNSTORE;
+
+INSERT INTO
+    t1
+VALUES
+    ('123'),
+    ('-123'),
+    ('5000000000'),
+    ('-5000000000'),
+    ('1.23'),
+    ('"123"'),
+    ('true'),
+    ('false'),
+    ('null'),
+    ('{"address": "Trondheim"}'),
+    (JSON_OBJECT()),
+    (JSON_OBJECT(1, 2)),
+    (JSON_ARRAY()),
+    (JSON_ARRAY(1, 2));
+
+SELECT
+    l AS raw,
+    JSON_VALID(l) AS is_valid,
+    JSON_VALID(JSON_COMPACT(l)) AS compact
+FROM
+    t1;
+
+--echo #
+--echo # String literal - invalid JSON
+--echo #
+TRUNCATE t1;
+
+INSERT INTO
+    t1
+VALUES
+    ('12 3'),
+    ('{key:value}'),
+    ('{key:value'),
+    ('[1,2,]'),
+    ('[1,2');
+
+SELECT
+    l AS raw,
+    JSON_VALID(l) AS is_valid,
+    JSON_VALID(JSON_COMPACT(l)) AS compact
+FROM
+    t1;
+
+--echo #
+--echo # String literal - not in UTF-8
+--echo #
+TRUNCATE t1;
+
+SET
+    NAMES 'ascii';
+
+INSERT INTO
+    t1
+VALUES
+    ('123');
+
+SELECT
+    l AS raw,
+    JSON_VALID(l) AS is_valid,
+    JSON_VALID(JSON_COMPACT(l)) AS compact
+FROM
+    t1;
+
+SET
+    NAMES 'utf8';
+
+--echo #
+--echo # Bare NULL
+--echo #
+TRUNCATE t1;
+
+INSERT INTO
+    t1
+VALUES
+    (NULL);
+
+SELECT
+    JSON_VALID(l)
+FROM
+    t1;
+
+--echo #
+--echo # Function result - string
+--echo #
+TRUNCATE t1;
+
+INSERT INTO
+    t1
+VALUES
+    (UPPER('"abc"'));
+
+SELECT
+    JSON_VALID(l)
+FROM
+    t1;
+
+--echo #
+--echo # Function result - string not in UTF-8
+--echo #
+TRUNCATE t1;
+
+SET
+    NAMES 'latin1';
+
+INSERT INTO
+    t1
+VALUES
+    (UPPER('"abc"'));
+
+SELECT
+    JSON_VALID(l)
+FROM
+    t1;
+
+SET
+    NAMES 'utf8';
+
+--echo #
+--echo # Function result - date, not valid as JSON without CAST
+--echo #
+TRUNCATE t1;
+
+INSERT INTO
+    t1
+VALUES
+    (CAST('2015-01-15' AS DATE));
+
+SELECT
+    JSON_VALID(l)
+FROM
+    t1;
+
+--echo #
+--echo # The date string doesn't parse as JSON text, so wrong:
+--echo #
+TRUNCATE t1;
+
+INSERT INTO
+    t1
+VALUES
+    (
+        CAST(
+            CAST('2015-01-15' AS DATE) AS CHAR CHARACTER SET 'utf8'
+        )
+    );
+
+SELECT
+    JSON_VALID(l)
+FROM
+    t1;
+
+--echo #
+--echo # Function result - NULL
+--echo #
+TRUNCATE t1;
+
+INSERT INTO
+    t1
+VALUES
+    (UPPER(NULL));
+
+INSERT INTO
+    t1
+VALUES
+    (UPPER(CAST(NULL AS CHAR)));
+
+SELECT
+    JSON_VALID(l)
+FROM
+    t1;
+
+DROP TABLE t1;
+
+DROP DATABASE json_valid_db;