Fix some issues with Microsoft SQL Server support

- Add in missing schema update for 1.23
- Fix detection of table/field existence
- Fix INSERT IGNORE support for cases where the primary key was being duplicated

Change-Id: Ia15673c869c2cf732ffe96f1608cee884d106ccd
(cherry picked from commit 1781729aa2db38681b4dd4cfbcfde48558c60fc1)