add support for SQL Server Query Hints

[donshop11]

the following query does not parse:

SELECT CustomerID, PersonID, StoreID
FROM cte
OPTION (MAXRECURSION 2);

see description here:
https://msdn.microsoft.com/en-us/library/ms181714.aspx

The value inside the OPTION is not that important to parse, it is more important not to fail parsing this kind of statements.

[fudianchn]

Root cause: the grammar has no production for the T-SQL OPTION (...) query hint clause, so any statement carrying one fails to parse.

PR #2472 adds it: OPTION (...) at the end of SELECT (including after set operations and FOR XML), UPDATE and DELETE parses into a new OptionClause holding OptionHints (keyword name + optional value or argument list). The statement from this issue parses into PlainSelect with MAXRECURSION 2 accessible from the AST and deparse round-trips unchanged; all query hint forms currently documented by Microsoft parse as well, and option stays a non-reserved keyword usable as column and table name.