Fix error when inserting to tables with datetime fields with QODBC

Fix error when inserting to tables with datetime fields with QODBC

SQL Server 10 introduced stricter rules for TIMESTAMP validation,
making it necessary to specify the decimal digits.
Other databases might do the same as well, so this patch introduces
a check for the TIMESTAMP column size and adjusts the decimal digits
parameter as needed.

Task-number: QTBUG-2192

Change-Id: If6d798c6c928ebda75bc474e49a07fbbfbe5816c
Reviewed-by: Mark Brand <mabrand@mabrand.nl>