[BE] - Refactor Mercadopago Backend

[dguglielmi-git]

Mercadopago's backend is highly coupled and the project structure is not MSC Architecture (Model-Service-Controller).

Currently, the controller is doing the whole job, We need to use the following approach:

• Structure the project must follow:
  • Controller: Receive the request and send it to the corresponding service
  • Service: Accept the request from the controller and process the data to reply to the controller once the data is processed as expected.
  • Model: should not contain any business logic, only the structure that will be mapped to the corresponding database.
• Separate the code taking into consideration the following points:
  • Verify Token
  • Calls to Owner Class (searchOwner, validateOwner, etc…)
  • Calls to Order Class (searchOrder, deleteOrder, etc..)
  • To apply SOLID patterns, we need to have these functions with a single responsibility, but some functions in the same body do more than one thing.

[dguglielmi-git]

Mercadopago SDK configuration was updated as indicated on the official website: https://www.mercadopago.com.ar/developers/es/docs/checkout-pro/integrate-preferences#editor_14