[LTI] HTTP 403 error when configuring Marsha on Blackboard due to incompatible role format

[wilbrdt]

Bug Report

Problematic Behavior
When configuring Marsha LTI on the Blackboard LMS, an HTTP 403 is raised.

Forbidden (Permission denied): /lti/select/classroom/
Traceback (most recent call last):
...
  File "/app/src/backend/marsha/core/views.py", line 1024, in post
    return self.render_to_response(self.get_context_data())
                                   ^^^^^^^^^^^^^^^^^^^^^^^
  File "/app/src/backend/marsha/core/views.py", line 298, in get_context_data
    self._init_context()
  File "/app/src/backend/marsha/core/views.py", line 879, in _init_context
    raise PermissionDenied
django.core.exceptions.PermissionDenied
"POST /lti/select/classroom/ HTTP/1.0" 403

Blackboard LMS set the role of an instructor to: urn:lti:role:ims/lis/Instructor,urn:lti:instrole:ims/lis/Faculty, which seems to follow the LTI 1.0 specification, but is not compatible with how Marsha checks the roles.

Expected behavior/code
Any LMS following the LTI 1.0 specification should be able to configure Marsha with LTI.

Environment

• Marsha version: 5.5.1

Possible Solution
As a first step, Marsha should be able to parse LIS roles.