feat: add Buttons and Links

gemeinsamforschen/src/main/webapp/assets/js/givefeedback.js

...nsamforschen/src/main/webapp/assets/js/project-student.js

gemeinsamforschen/src/main/webapp/assets/js/utility.js

gemeinsamforschen/src/main/webapp/assets/js/viewfeedback.js

gemeinsamforschen/src/main/webapp/pages/givefeedback.jsp

gemeinsamforschen/src/main/webapp/pages/project-student.jsp

gemeinsamforschen/src/main/webapp/pages/viewfeedback.jsp