add teacher_menu to UI
add options for teachers to add, list, or remove teachers and students.
make menu options more visually pleasing.
add student_menu to UI.:
fix typos in UI.
add add_teacher method to UI.
add add_student method to UI.
revamp teacher menu to list all teachers right at the start.
add menu options after selecting a specific teacher.
place list_teachers method after student_menu.
add method for reading teacher ids in Teacher class.
add method for reading student ids in class Student.
add method for removing teachers in UI.
revamp student menu to list all students right at the start.
add method for removing a student in UI.
add method for updating a teacher's apparatus. WIP.
add method for listing teachers by apparatus
add method choose_teacher to UI.
add method students_assigned_to_teacher to UI.
add option to unenroll a student in UI's students_assigned_to_teacher method.