Adds a new certified FedEx delivery module to support FedEx certification requirements and updated API behavior. This helps businesses use FedEx shipping in Odoo with changes aligned to FedEx guidelines and room for future FedEx options without database restructuring.

For the certification process of FedEx there were some changes needed in the delivery_fedex_rest module.
This modules made those changes according to the FedEx guidelines.

Task-id: 6164275