FEAT - Limit the characters allowed in course title
FEAT - Limit the characters allowed in course title

- added regex to check if course title contains accepted characters only
  (accepted characters are letters, numbers, and "-_.")
- This change was made to accomodate a request made by Gehad for the
  branch: feature_backend_addStudentToCourses

Jacob-Manuel/swe4103-group1,Jacob-Manuel/swe4103-group1