Add easy access simulation page (for the navbar)

[e-caste]

The page should be accessible from the "Simulation" button in the navbar.

Contains:

• dropdown with all the courses the user is enrolled in
• "Start" button which is enabled once a course is selected -- the button should just go to the same page where you go when you go to when you click "Start Simulation" on the course's page
• List of the user's simulation results

Also take a look at my drawing 😎

[itIsJim]

TODO:

• [x] CSS design of the page