Use @hierarchy annotation

[agoerler]

No description provided.

[eugene-andreev]

I've discussed the problem with @hierarchy and drafts with Elena, she will have a look, why the EDMX differs

[eugene-andreev]

Checked once again in a call with Elena:

1. We've forgotten to do the change
2. Removing package-lock.json and node_modules and rebuild helped to solve the issue.

Now both read and write for Genres are working fine