* Failing test for one2many [(5,)] action, when domain is callable.

The problem is that `self` inside a callable domain becomes the comodel when at [(5,)].

* [FIX][fields] Make [(5,)] with computed domain work.

To reproduce this failure, declare a field like:

```
child_ids = fields.One2many(
    comodel_name="other.model",
    domain=lambda self: [("id", "in", self._ids_to_find())],
)
```

Now set some value to it.

Now unset them. Impossible because ``self`` becomes ``other.model`` in domain evaluation.