add saving status and basic test for this

ormar/queryset/queryset.py

@@ -358,8 +358,10 @@ class QuerySet:
             instance.pk = pk
 
         # refresh server side defaults
-        instance = await instance.load()
-
+        if any(field.server_default is not None
+               for name, field in self.model.Meta.model_fields.items() if name not in kwargs):
+            instance = await instance.load()
+        instance.set_save_status(True)
         return instance
 
     async def bulk_create(self, objects: List["Model"]) -> None:
@@ -372,6 +374,9 @@ class QuerySet:
         expr = self.table.insert()
         await self.database.execute_many(expr, ready_objects)
 
+        for objt in objects:
+            objt.set_save_status(True)
+
     async def bulk_update(
         self, objects: List["Model"], columns: List[str] = None
     ) -> None:
@@ -418,3 +423,6 @@ class QuerySet:
         # otherwise it just passes all data to values and results in unconsumed columns
         expr = str(expr)
         await self.database.execute_many(expr, ready_objects)
+
+        for objt in objects:
+            objt.set_save_status(True)