Return SQL types as part of the cursor result

The result of a query includes a descriptor with the header information. I noticed that this header information uses the Python type description, while I expected the SQL type description. For considering a simple table rendering based on a fetchall: row-1 columnnames, row-2 sql type names, row-* the actual rows. Should this be fixed or become an alternative entry in the Description as it is DBAPI requirements

Describe the solution you'd like
The Description should be extended with the types obtained from MonetDB itself.

Related to #119