[FIX] pos_daily_sales_reports: use pos config currency when possible

Current behavior:
The currency used to create the report is the one of the company. But
if you use a different currency in the pos config, the report will still
be in the company currency.
To fix that we check if all report's config use the same currency and
use it if it's the case we use the pos config currency. And if it's not
possible we use the company currency.

Steps to reproduce:
- Create a second pos
- Change the sale journal and the pricelist to use a different currency
- Open a session and make a sale
- Close the session
- Generate the daily report for the second pos
- The currency is the one of the company

opw-3463280

closes odoo/odoo#132852

Signed-off-by: Joseph Caburnay (jcb) <jcb@odoo.com>