StatementParser only supports one query hint

[elefeint]

Hello! We've found an obscure select query that the statement parser does not support yet.

Observed behavior

The following evaluates to false:

boolean isQuery = StatementParser.INSTANCE.isQuery("@{FORCE_INDEX=index_name} @{JOIN_METHOD=HASH_JOIN} SELECT * FROM tbl");

Expected behavior

Query Statement with multiple hints is recognized as a valid query.

External references such as API reference guides

Spanner queries can have one of each: query, table and join hint preceding SELECT statement.

Any additional information below

We found this when migrating R2DBC driver from a custom statement parser to the connection API one; this test caught the issue.

[elefeint]

cc/ @dmitry-s