Add favorite icon to comment-component, button for creator

src/app/components/shared/comment/comment.component.html

@@ -5,6 +5,9 @@
     <button mat-icon-button [disabled]="userRole === 0" (click)="setCorrect(comment)" [matTooltip]="comment.correct ? 'Antwort richtig' : null">
       <mat-icon [ngClass]="{'correct-icon' : comment.correct === true}">check_circle</mat-icon>
     </button>
+    <button mat-icon-button [disabled]="userRole === 0" (click)="setFavorite(comment)" [matTooltip]="comment.favorite ? 'mark as favorite' : 'mark as not favorite'">
+      <mat-icon [ngClass]="{'favorite-icon' : comment.favorite === true}">star</mat-icon>
+    </button>
     <button mat-icon-button [disabled]="userRole === 0" (click)="setRead(comment)" [matTooltip]="comment.read ? 'mark me as unread' : 'mark me as read'">
       <mat-icon [ngClass]="{'read-icon' : comment.read === true}">visibility</mat-icon>
     </button>

src/app/components/shared/comment/comment.component.scss

@@ -25,3 +25,7 @@ mat-icon {
 .read-icon {
   color: blue;
 }
+
+.favorite-icon {
+  color: #fdd835;
+}

src/app/components/shared/comment/comment.component.ts

@@ -43,6 +43,11 @@ export class CommentComponent implements OnInit {
     this.commentService.updateComment(comment).subscribe();
   }
 
+  setFavorite(comment: Comment): void {
+    comment.favorite = !comment.favorite;
+    this.commentService.updateComment(comment).subscribe();
+  }
+
   delete(comment: Comment): void {
     this.commentService.deleteComment(comment.id).subscribe(room => {
       this.notification.show(`Comment '${comment.subject}' successfully deleted.`);