Consider the following scenario: open in edit mode a form view
containing a many2many field displayed with widget many2many_tags,
on the many2many field dropdown, click on 'Search More' (it opens
a dialog), and in the dialog, try to save the current search in
the searchview's favorite menu.
Before this rev., it tried to retrieve the context of the active
view in the closest instance of a ViewManager-like widget in the
SearchView's ancestors.
First, it is wrong as in the given scenario, the requested context
is actually the one of the list controller in the dialog, not the
one of the form controller in the background.
Second, it produces a crash in Studio, when trying to save filters
in the dialog opened by clicking on 'Search More' on the groups
many2many field in the sidebar.
This part of the code can't be tested in this version, but tests
will be added in master.
Fixes#23293