Currently, when we create time off and does not add 'Start Date' or
'End Date', it displays a wrong warning.
Issue is occur because date_from is required field at db level and it's
value computed based on visible field request_date_from which is
non-required field and when you keep that empty it will raisse the
contraint instead of required error.
So in this commit, we make request_date_field field required from view
and also make request_date_to visible based on condition so it should
fill the proper value inside the date_from and date_to.
closesodoo/odoo#63222
Taskid: 2352360
X-original-commit: c54f445ceae72518f787f43213ec78a9a7e1b1eb
Signed-off-by: Yannick Tivisse (yti) <yti@odoo.com>