Renamed groups to roles in the frontend

Working:
 Account
 Cost Centre
 Employee
 Product Group
 Product
 Role
 User
 Client

overlord/src/app/client/client.service.ts

@@ -27,8 +27,7 @@ export class ClientService {
   }
 
   list(): Observable<Client[]> {
-    const options = {params: new HttpParams().set('l', '')};
-    return <Observable<Client[]>>this.http.get<Client[]>(url, options)
+    return <Observable<Client[]>>this.http.get<Client[]>(`${url}/list`)
       .pipe(
         catchError(this.log.handleError(serviceName, 'list'))
       );