Purpose
=======

In Belgium, we need to support some partial time on 2 weeks.
For instance, a mid time, means you could work on monday, tuesday
and wednesday on week1 and monday and tuesday on week 2. Others payroll
softwares manage this.

Specification
=============

Add a checkbox on resource calendar to manage 2 weeks. --> Consider even/odd weeks.
Add sections on calendars (Like sales orders)
Modify methods in resources to apply this behavor generically.

Check that attendances aren't overlapped

Write an integration test for holidays - benefits - payslip
to check all this, + "credit temps" and wage modification.

Note
====

For the sake of simplicity, we only manage calendars over 2 weeks
to consider the odd/even weeks and keep an easy implementation.
For more complicated calendars (eg: over a months with specific targetted days),
it's better to create specific allocation requests and apply specific leaves
for those days, as it would be the case for parental leaves.

closes odoo/odoo#31674

Signed-off-by: Yannick Tivisse (yti) <yti@odoo.com>

Resource module defines some demo data that are not used anywhere.
Moreover using resource module on its own does not give interesting
results as this is a tool module used in various addons like holidays
or project issue.

Those modules define their own demo data that will have an impact on
resource. It is therefore not necessary to define specific demo data
that does not help the user in any way.

Purpose of this commit is to always have a default calendar for each
company and ensure it is correctly set on resources.

Some cleaning is also performed in resource models to remove unused
fields, improve labels and make views a bit more odoo-ish.

 * [REF] res_company: add a m2o to the default calendar to use in the
   company as well as a o2m linking all resource calendars used in the
   company. Some code has been added to correctly update existing
   companies when installing the module;
 * [REF] resource_calendar
  * [REM] manager field on resource.calendar: this field is never used
    and is not necessary anyway
  * [ADD] global_leave_ids: filter leaves on a calendar to see global
    company leaves
  * [IMP] better default company / calendar computation to ensure there
    is always a calendar attached to a resource
  * [IMP] improve resource and calendar views in order to look more like
    other odoo views

Currently there is no default resource calendar. This leads to calendar
being rarely used as it is not clear how to define them and how to use
them. Moreover some code handle default-like calendar by trying to
use 8-16 work hours; this should be replaced by having a real default
calendar.

This commit replaces the demo calendar by a real data calendar. It will
soon be used as default everywhere a resource calendar can be defined.

Future improvements will come to make resource easier to use and clean
its API. This commit is only the beginning !