Change some ``ref`` to low level method ``_xmlid_to_res_id``. The latter one
does not call exists, which allows to gain one query that we do not need
here.
Default methods on activity / activity mixin to find the default activity
type (todo, model-based, generic) are cleaned. Notably code was duplicated
between mixin and activity, it now always call the same code.
Remove an unnecessary ref, probably a leftover of new rendering methods on Qweb.
Remove an unnecessary sudo.
Task-2883589 (Activity performance and cleaning)
Part-of: odoo/odoo#93682
Thibault Delavallée
115f5663f1