To reproduce:
=============
- with `hr_contract` and `helpdesk` installed
- create a user with 2 resources in 2 different companies
- add the user as member of a helpdesk team of company A
- enable auto assignment on the team
- try to create a ticket on that team -> error

Problem:
========
When computing working intervals for resources of the team members,
we were considering all resources of the user, even those not in the same
company as the helpdesk team. Which lead to access errors when trying
to read data from the other company.
This issue was not caught before as we were never reading data from the
resources, until this [commit](https://github.com/odoo/odoo/commit/79a559c9741410ad861c107e395b2fc486da95e8)
where we try reading `employee_id` of the resource.

Solution:
=========
Filter resources to keep only those in the same company as the helpdesk team.

P.S:
====
the removed test was trying to test assigning ticket to user that is not
in the same company as the helpdesk team, which is not correct so the test was removed.

opw-[2749232](https://www.odoo.com/web#id=2749232&view_type=form&model=project.task)

Forward-Port-Of: odoo/enterprise#99614

When refunding an order that originally had a global discount, if you didn't refund the discount, the refund total amount would exceed the original order total. This would cause issues when trying to generate a global invoice for the mexican localization.

Steps to reproduce:
-------------------
* Activate the global discount option in any PoS
* Open PoS and make a sale with a global discount
* Refund the sale without including the discount
* Go to the backend
* Go to the order list and select the 2 orders you made
* Now try to create a global invoice
> Observation: The global invoice is in error because the negative lines
  cannot be distributed correctly.

Why the fix:
------------
To avoid this issue with the global invoice we simply prevent the user to generate a refund with a greater amount than the original order. We only apply this limit to the mexican localization because it's the only module that is affected by this issue. Other localizations can still refund without restrictions even if this work flow does not really make sense.

opw-4899501

Forward-Port-Of: odoo/enterprise#93101