Develop

modified course table functionality:

- for who failed some courses, the table displays the courses in the current level and in the next level
- for who passed all the courses, the table displays only the next level and all checked
- for who in the highest level and passed all the courses, the table doesn't display anything since the student does not need to take anything
- for who in the highest level and failed some courses, the table displays only the current level courses

:)