### To merge in 17.0 to master  -.1

Bugs:
-----
1.
both: -go to time off and click on "New Allocation Request"
      -change the allocation type to any other

2.a
-> the number of days or hours is set to 0 where it should be 1 day
   or 8 hours/ressource callendar of the employee

2.b
-> if you have selected an allocation where the unit is "half_day" or
   the number of days and the title doesn't corresponds to each other

First introduction:
-------------------
    task: 3084232
    PR: https://github.com/odoo/odoo/pull/116472

Reasons:
--------
a. We where using the fields where were made for the front-end only
   and where not computed properly and thus resetting the value to 0
   when changing the allocation type

b. The title was using the unit of the allocation type in db and not
    Labels or the unit of the allocation duration

Fixes:
------
Not use the display fields for the computation of the title and make labels corresponding to the actual unit of the allocation duration

task-3852940

Description of the issue/feature this PR addresses:

Current behavior before PR:

Desired behavior after PR is merged:




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Forward-Port-Of: odoo/odoo#161035