Portability fixes for SchemaBuilder on MSSQL
Portability fixes for SchemaBuilder on MSSQL

Changed binary mapping to `varbinary(max)` on MSSQL instead of `binary(1)` (which requires a length and is fixed length)
to better match other dbms.

Changed timestamp mapping to datetime on MSSQL. Timestamp is a unique number on MSSQL, not a timestamp.

separated from #9191

gowsigan001/yii,gowsigan001/yii,gowsigan001/yii,gowsigan001/yii