With this commit, we prevent view dialogs from changing the 'global'
environment in the view manager. Here is how it could cause a problem:
* open a form view for a bill of material
* click on one of the component, it will open a form view in a dialog
(and will change the environment with a wrong res_id)
* click on the many2one product -> it will open a new action in the
background, and change the environment again
* click on the breadcrumb to come back to the bill of material: the view
manager will try to restore the correct res_id (which is the wrong id
from the component form view), the form view will do a read (when
reloading the data), will get an empty result, will update its
information with no data, then will be in a wrong state which means
that the basicmodel will fetch a x2many with a wrong res_ids list
* boom