Before this commit, the calendar filter was a little bit limited: you could add filters to only display events related to these filtered records or display all events.
If you wanted to select all active filters, we had to check all these individual filter.
This commit introduce the possibility to select all existing filter at once or to unselect them. It is quite convenient when a lot of filter are displayed but unchecked.
Taskid: 2484335
Part-of: odoo/odoo#68700
Arnaud Joset
57dbfff2db