Extract course participation panel

[dirkriehle]

See UI layout

Extract Course Participation panel

• Extract panel from Settings panel (Project Lists part)
  • Add as new panel next to User Profile panel
• Coordinate with related issue

On Course Participation panel

• Create two sections (Enrolled courses, Available courses)
• Under enrolled courses, provide table listing the courses the user is participating in
  • Add leave button
• Under available courses, provide (second) table listing all courses the user is not participating in
  • If course allows for it, add join button

Definition of done

• Removed two open linting issues
• Successfully merged into mainline on riehlegroup/mini-meco

[MikeFAU]

@dirkriehle: How should it be determined whether the user is allowed to join the course? I didn't find any reference to this in the current implementation