Add lookup addCondition issue to demo

[mhuser]

NOT TO BE MERGED

In atk4/ui 2.2.x it is possible to addCondition() to a form control lookup->model.
In atk4/develop it is still possible to addCondition() at initialization of the lookup, but not after. This PR add a segment to lookup-dep demo to show both at init or after addCondition behaviour on lookup.

[mvorisek]

@georgehristov do we duplicate somewhere the model without cloning it, so the conditions are unset? That is what I think is the issue.

[mhuser]

@mvorisek , @georgehristov seems adding this to renderView() fix the behaviour:

    $this->callback = \atk4\ui\Callback::addTo($this);
    $this->callback->set([$this, 'outputApiResponse']);

Not sure what it is doing.
These lines have been moved to init()

[mvorisek]

@ibelar I think you want the one who moved this part, please check

[ibelar]

@ibelar I think you want the one who moved this part, please check

@mvorisek - Yes - It was moved to fix #1462

[mvorisek]

@ibelar I think you want the one who moved this part, please check

@mvorisek - Yes - It was moved to fix #1462

but for some reasons no PR is linked there...

[ibelar]

Close because replace by #1558