[17.0][FIX] contract: report translations & change structure

[peluko00]

Description of the problem:
Go to Invoicing -> Customer Contracts and try to print a contract.
Normally when you print a contract the default language of that one bases on customer language but not works in that report.
Example:
Your default language is Spanish and your customer's default language is English
Try to print the report and you see that the report prints in Spanish and not in English.
I changed the structure because i'm base of the report of an invoice from the odoo's core structure(see more in the links below):

https://github.com/odoo/odoo/blob/17.0/addons/account/views/report_invoice.xml#L429
https://github.com/odoo/odoo/blob/17.0/addons/account/views/report_invoice.xml#L4

I test that structure first and works perfect and I try to reproduce in that case and works fine.

contract_report_failed.webm

contract_report_works.webm

[peluko00]

Fixed Module report

cc https://github.com/APSL 154355

@miquelalzanillas @lbarry-apsl @javierobcn @mpascuall please review

[lbarry-apsl]

Validated functionality in Runboat