Before this comit:
The `_views_get()` method would be called recursively for every
`inherit_children_ids`.
At the end of the method, we would get the complete view hierarchy, including
duplicate hierarchies for website specific copies (COW).
Then, the `get_related_views` that is calling `_views_get()` would be overriden
in website module to keep only most specific views.
But this would not be enough as it would leave orphans from other trees:
- Have a base view 'B'
- That has an inherited view 'I'
- That has itself an inherited view 'II'
- Now make the hierarchy specific on a website from 'I'
- And add another inherited view to 'I' on the generic tree
This become:
B
/ \
/ \
I I'
/ \ |
II II2 II'
As explained, filtering duplicates would not be enough as it would correctly
remove 'I' and 'II' from the generic tree but would not remove 'II2'.
At the end, it would return "B", "II2", "I'" and "II'".
Now, we correctly return only "B", "I'" and "II'" by ignoring generic trees
when there is a specific one.
Closes#29347