engines moved to separate library

lib/engines/mssql/primary_keys.sql

@@ -0,0 +1,12 @@
+select o.object_id, pureName = t.Table_Name, schemaName = t.Table_Schema, columnName = c.Column_Name, constraintName=t.constraint_name from 
+    INFORMATION_SCHEMA.TABLE_CONSTRAINTS t,
+    sys.objects o,
+    sys.schemas s,
+    INFORMATION_SCHEMA.CONSTRAINT_COLUMN_USAGE c
+where
+    c.Constraint_Name = t.Constraint_Name
+    and t.table_name = o.name 
+    and o.schema_id = s.schema_id and t.Table_Schema = s.name
+    and c.Table_Name = t.Table_Name
+    and Constraint_Type = 'PRIMARY KEY'
+	and o.object_id =[OBJECT_ID_CONDITION]