Programme coordinator

Adds rights for the programme coordinator and programme director roles and tests to check these rights. Programme coordinators and directors can create courses and course editions only for the programme they are coordinator/director for. In addition, they can manage course participations and imports.

• Renamed academic counsellor to programme coordinator
• Renamed counsellor (on individual course) to enrollment manager
• Added migration for academic counsellor to programme coordinator
• Fixed permissions regarding course participations
• Fixed counsellor not being able to create course participations
• Added role checking on programmes
• Added tests for programme coordinator access
• Added tests for verifying that students cannot access the admin panel
• Instead of hardcoding "course coordinator" or "counsellor" in the message, use I18n for consistent naming.

Closes #116 (closed)