Remove duplicate fields in tree views / kanban (outside of templates).
A field should not be present twice in a tree view. If one of the nodes has
custom attributes then behavior of other nodes is somehow unpredictable.
Having field present only once gives a more coherent behavior. Xpaths
could also lead to weird results if fields are present several times as
developers generally do not expect fields to be present several times in a
view.
An heuristic to detect duplicate fields will land soon in master. As this
commit targets a stable version only view fixes are provided.
Task ID-2329114
PR odoo/odoo#56946
X-original-commit: 977c2b9d12419fba3bada1ebefcca15f051ca565
Victor Feyens
e261cddd73