Remove new feedback option for all but the latest submission

Removes the feedback and grade form from old submissions.

src/main/java/nl/tudelft/submit/service/StudentGroupService.java

@@ -108,18 +108,25 @@ public class StudentGroupService {
 							assignment.setScoreType(assignmentService.getOrCreateSubmitAssignment(a.getId())
 									.getScoreType());
 							return assignment;
-						},
-								a -> submissionService.getSubmissionsOfAssignmentForGroup(a.getId(), id)
-										.stream()
-										.sorted(Comparator.comparing(SubmissionDetailsDTO::getSubmissionTime)
-												.reversed())
-										.map(s -> {
-											SubmitSubmissionViewDTO view = mapper.map(s,
-													SubmitSubmissionViewDTO.class);
-											view.setFeedback(
-													feedbackService.getAllFeedbackPerSubmission(s.getId()));
-											return view;
-										}).collect(Collectors.toList()))));
+						}, a -> {
+							var submissions = submissionService
+									.getSubmissionsOfAssignmentForGroup(a.getId(), id)
+									.stream()
+									.sorted(Comparator.comparing(SubmissionDetailsDTO::getSubmissionTime)
+											.reversed())
+									.map(s -> {
+										SubmitSubmissionViewDTO view = mapper.map(s,
+												SubmitSubmissionViewDTO.class);
+										view.setIsLatest(false);
+										view.setFeedback(
+												feedbackService.getAllFeedbackPerSubmission(s.getId()));
+										return view;
+									}).collect(Collectors.toList());
+							if (!submissions.isEmpty()) {
+								submissions.get(0).setIsLatest(true);
+							}
+							return submissions;
+						})));
 		group.setSubmissionMap(assignments);
 
 		if (isStaff) {