On a form view of model A, if a many2one field (model B) has a [tree|form]_view_ref in the context
(to display a custom 'Search More...' tree view dialog for example),
when clicking on this field to display the model B form view, the context key *_view_ref is passed
when loading subviews (model C) making them crash because the view ref corresponds to the model B.
After this commit, '*_view_ref' keys in the context are dropped when loading subviews
closesodoo/odoo#29022