UI component for allowed requests for students with multiple roles

What does this mr do?

This MR enables people with both staff and student roles in a shared lab to differentiate between the assignments they can enqueue for vs the assignments they can take requests for in the lab enqueueing page. The affected UI component is highlighted in a picture below.

Note: this change only applies for persons with multiple roles (ie. both staff and student roles) in one lab.

UI change suggested by @rwbackx .

Screenshots

before

In the old version, only the allowed assignments one could enqueue for were shown

after

In the new version, all assignments associated with the session are shown. Moreover, for people with multiple roles, the assignments for which they can enqueue for versus take requests for are highlighted in different sections.

Does this MR meet the acceptance criteria?

• I have added a changelog entry to reflect the significant changes I made.
• Tests were created to test the feature.
• I have updated the documentation accordingly.
• I adhere to the style guide.

Closes #571