WIP: Resolve "answer statistics (logic)"

Information

• added responded answer statistic for choice and text answers
• added evaluation overview for choice answers (no api connection, no in-memory-data)

Testing

• checkout answer statistic room
• check functionality
• give feedback about the style

Closes #113 (closed)

src/app/creator-room/creator-room.component.html

@@ -30,9 +30,6 @@
         <button mat-button color="primary" matTooltip="See answer statistics" routerLink="/creator/room/{{room.id}}/answer-statistics">
           Answer statistics
         </button>
-        <button mat-button color="primary" matTooltip="See answer statistics" routerLink="/creator/room/{{room.id}}/answer-statistics">
-          Answer statistics
-        </button>
         <button *ngIf="!modify" (click)="showEditDialog()" mat-button color="primary">
           Edit room
         </button>