Implement student and course page

.../ui/cs/advprog/tutorial0/controller/CourseController.java

...ui/cs/advprog/tutorial0/controller/StudentController.java

...og/tutorial0/exception/DuplicateStudentNameException.java

...ac/ui/cs/advprog/tutorial0/exception/EmptyCourseName.java

...main/java/id/ac/ui/cs/advprog/tutorial0/model/Course.java

...ain/java/id/ac/ui/cs/advprog/tutorial0/model/Student.java

.../ui/cs/advprog/tutorial0/repository/CourseRepository.java

...ui/cs/advprog/tutorial0/repository/StudentRepository.java

.../id/ac/ui/cs/advprog/tutorial0/service/CourseService.java

...ac/ui/cs/advprog/tutorial0/service/CourseServiceImpl.java

...id/ac/ui/cs/advprog/tutorial0/service/StudentService.java

...c/ui/cs/advprog/tutorial0/service/StudentServiceImpl.java

src/main/resources/templates/courseList.html

src/main/resources/templates/createCourse.html

src/main/resources/templates/createStudent.html

src/main/resources/templates/studentList.html