feat: récupération sommaire des groupes de tâches

src/services/group.service.ts

@@ -0,0 +1,10 @@
+import { Service } from '@angular/core';
+import { BaseService } from './base.service';
+import { Observable } from 'rxjs';
+import { Group } from '../model/Group';
+@Service()
+export class GroupService extends BaseService{
+  public getGroups():Observable<Group[]>{
+    return this.get<Group[]>("http://127.0.0.1:8080/group");
+  }
+}