Simulate grades in academic pathway

[fabiodrg]

This PR is a take to close #64.

Approach:

• Adds a button near the table to launch a Modal
• The Modal lists all courses found in the table, the achieved grade (if any), and an input where the user can insert a new grade for simulation. Upon user input, it changes the average achieved in the degree

Bonus in the implementation:

• Handle missing courses. The table, as far as I remember, is partial, i.e. it only shows courses subscribed. Thus a student in the second year bachelor won't see the third year courses. We can have an additional input for the unknown courses, allowing the user to estimate the average for the full course
• Define target. Additionally, there could be an option to type the desired conclusion grade and it would estimate the necessary average grade for unfinished courses