Move question.service.ts to shared services folder

Author: limcaaarl

frontend/src/app/questions/question.service.spec.ts renamed to frontend/src/_services/question.service.spec.ts

@@ -1,9 +1,9 @@
 import { HttpClient, HttpErrorResponse, HttpHeaders, HttpParams } from '@angular/common/http';
 import { Injectable } from '@angular/core';
-import { API_CONFIG } from '../api.config';
+import { API_CONFIG } from '../app/api.config';
 import { catchError, Observable, throwError } from 'rxjs';
-import { SingleQuestionResponse, QuestionResponse, QuestionBody } from './question.model';
-import { TopicResponse } from './topic.model';
+import { SingleQuestionResponse, QuestionResponse, QuestionBody } from '../app/questions/question.model';
+import { TopicResponse } from '../app/questions/topic.model';
 
 @Injectable({
     providedIn: 'root',

frontend/src/app/questions/question.service.ts renamed to frontend/src/_services/question.service.ts

@@ -17,7 +17,7 @@ import { Column } from './column.model';
 import { Topic } from './topic.model';
 import { Difficulty } from './difficulty.model';
 import { DifficultyLevels } from './difficulty-levels.enum';
-import { QuestionService } from './question.service';
+import { QuestionService } from '../../_services/question.service';
 import { forkJoin } from 'rxjs';
 import { HttpErrorResponse } from '@angular/common/http';