sql.JsonDocument ToString returns strings without whitespaces

[druvv]

The sql.JsonDocument ToString method uses json.Marshall. This returns a string without any extraneous whitespace. MySQL on the other hand uses whitespaces for legibility:

mysql> CREATE TABLE t1 (c1 JSON);

mysql> INSERT INTO t1 VALUES
     >     ('{"x": 17, "x": "red"}'),
     >     ('{"x": 17, "x": "red", "x": [3, 5, 7]}');

mysql> SELECT c1 FROM t1;
+------------------+
| c1               |
+------------------+
| {"x": "red"}     |
| {"x": [3, 5, 7]} |
+------------------+

Notice that there is additional whitespace between the semicolon of a key/value pairs and between the comma of array elements.

In Dolt's new storage format, we use sql.JsonDocument for JSON columns. Previously we used json.NomsJson which implements ToString correctly.