refactor: update integration tests workflow and add pytest configuration

[magajh]

Description

This PR includes some necessary changes to use the updated integration testing action https://github.com/eduNEXT/integration-test-in-tutor. The changes are described below:

• Added pytest and pytest-django requirements to run the tests.
• Updated the integration test workflow to use the updated action.
• Modified the target in the Makefile to use pytest for running unit tests, ensuring consistency in how tests are executed across all plugins.
• Added a target in the Makefile and a script to run the integration tests.
• Moved integration tests for the backends and the info view to the integration folders.

For more information about the changes and the reasoning behind them, please refer to the documentation on writing integration tests for the plugins: https://internal.docs.edunext.co/en/latest/internal/Teams/Descontrol/Internal_processes/integration_tests_in_plugins/integration_tests_with_openedx_components.html

Note for Reviewers

This PR does not move the unit test files to unit/ folders. That effort will be part of a future PR when integration tests are added to the plugin.

How to Test

Ensure that both unit and integration tests pass without issues in the GitHub CI/CD pipeline.

[BryanttV]

Thanks @magajh, LGTM! Just remember to update the branch of the integration tests action.

[MaferMazu]

My only comment here is we can use the main or release version of the integration test action. The rest looks good to me. Thanks ✨

[magajh]

@MaferMazu @BryanttV thank you both for the review! I've updated the action branch to main and removed the input