Log of new engine SQL rest action has broken format and exposes raw query

[chloe-zh]

Issues:

1. Log format has invalid new lines ("\n"), see following example
2. Raw SQL queries are exposed in log

Example:
sql query:

POST _opendistro/_sql
{
  "query" : """
        SELECT a.f, a.l, a.a
        FROM (
          SELECT firstname AS f, lastname AS l, age AS a
          FROM bank
          WHERE age > 30
        ) AS a
        """
}

log:

[2020-11-11T13:06:30,530][INFO ][c.a.o.s.l.p.RestSqlAction] [a483e711985a.ant.amazon.com] [20a5b64a-bce9-4d4c-a661-9be055eb3fdc] Request SQLQueryRequest(jsonContent={"query":"\n        SELECT a.f, a.l, a.a\n        FROM (\n          SELECT firstname AS f, lastname AS l, age AS a\n          FROM bank\n          WHERE age > 30\n        ) AS a\n        "}, query=
        SELECT a.f, a.l, a.a
        FROM (
          SELECT firstname AS f, lastname AS l, age AS a
          FROM bank
          WHERE age > 30
        ) AS a
        , path=/_opendistro/_sql, format=jdbc) is handled by new SQL query engine

[dai-chen]

Will fix this. Thanks!