Stack of relations forms

I can create stack of features forms for 1-N relations features and they are available to edit, even then they are deleted.

Scenario:

1. open tc04_relations project
2. create and distring and add at least one natural to it and save both
3. then open the district and click on the natural -> this opens form of the natural
4. now click on the district -> this will open form of the district
5. now click on the natural again -> this opens form of the district
6. repeat this multiple times and stop on the district form
7. now remove the district and confirm the deletion
   -> now you can see that in the natural form, district is still visible

• when you hit it, the already deleted district opens an you can edit it (add naturals .. ) but when you save it nothing happens
• when you hit arrow in the top left corner, you will go though the stack of forms back for even deleted feature.

https://user-images.githubusercontent.com/83582181/196796783-d285b472-e238-4da4-830c-5bdac40a50fb.mp4

Start by reproducing the stack-of-forms scenario in the tc04_relations project, following the numbered steps and reviewing the linked video. Confirm that deleting the district removes it from the natural form and that back navigation no longer reaches deleted forms; the payload names no source files or tests.