The old tree views don't really exist anymore, this odd pseudo-flag to
dispatch between "list" and "tree" tree views has no reason to remain.
Task 1937686
closesodoo/odoo#31243
Signed-off-by: Xavier Morel (xmo) <xmo@odoo.com>
Purpose of this commit is to ease project managers in their daily job
organization by ensuring that newly created activities in project
configuration are by default associated to tasks, and not global.
Activity types actions and views are moved in their own file in order
to match the guidelines.