Fix traversal when parent model is loaded

[mvorisek]

finish after #855, #860, #861

discussion here: c8cbce3#r49718142

fixes https://github.com/mvorisek/atk4-hintable-mirror/blob/1.2.1/tests/Data/HintableModelTest.php#L120

$model = new Model\Standard($db);
$model->load(2)->simpleMany->loadAny()->id;

must traverse from model with ID = 2 only (before this PR, ID = 2 condition was not applied and it was required to be added manually, now with entity concept we can assume locked ID)

note: this works also with $model->load{One, Any}()->simpleMany and also with Model::duplicate() which will unset the ID correctly.

[DarkSide666]

Overall I don't think this is correct approach.
Loading record shouldn't add condition to model because that will limit how getTitles(), export() and other dataset-wise methods will work when model is or is not loaded. That shouldn't happen.

[mvorisek]

All changes reverted and addressed differently, getTitles() and other confusing behaviour with entity (loaded model) now thow because of #855

[mvorisek]

FYI: having with group by is like where, but it does not apply after aggregate functions.

[DarkSide666]

Approved in advance. Need to fix this approach for MS SQL