:sparkles: (backend) django admin app for batch orders

[jonathanreveille]

Purpose

We need admin user to be able to create batch order through the admin of the django. They will be able to create, assign, submit to signature the contract and generate orders once they have received the payment. We will also add the action to cancel a batch order.

The admin django for batch orders will create all the necessary objects as if it was going through the API. The advantage of using the admin of django, admin user will be able to force an organization id while creating a batch order.

Proposal

• [x] create new mail MJML template and debug view for invitation signature link.
• [x] create a django admin app for batch order (create, update, read, list, cancel).
• [x] create utils method for batch order (send_invitation_link by email, validate_success_payment, generate_orders and send_mail_vouchers by email)