AutoAssign primary key

If structure has `AutoAssign` primary key the following code does not produce expected result

```cpp
entity entry{ .pk = 10, .message = "hello"};
dm.Create(entrty);
// entry.pk is not 10
```
the work around is following
```cpp
entity entry{ .message = "hello"};
entry.pk = 10; // This will mark it as modified
dm.Create(entrty);
// entry.pk is 10
```