NH-3408 - Fix mapping for non MS SQL Server dialects
NH-2408 - Mark fixture as for Microsoft SQL Server dialects only
NorthwindDbCreator - split CreateNorthwindData to methods and use dictionaries instead of linq queries to avoid StackOverflowException when tests are being ran by ReSharper's test runner on x64 machine.
(cherry picked from commit c263598f703779fde39c4267b843f9e2ce5a212c)