Add enpoint for room stats and query on room page

src/app/components/shared/room-page/room-page.component.ts

 import { Component, OnInit } from '@angular/core';
 import { Room } from '../../../models/room';
+import { RoomStatistics } from '../../../models/room-statistics';
 import { RoomService } from '../../../services/http/room.service';
 import { ActivatedRoute } from '@angular/router';
 import { Location } from '@angular/common';
@@ -17,6 +18,7 @@ export class RoomPageComponent implements OnInit {
   isLoading = true;
   commentCounter: number;
   protected moderationEnabled = false;
+  protected roomStatistics: RoomStatistics;
 
   constructor(protected roomService: RoomService,
               protected route: ActivatedRoute,
@@ -60,6 +62,9 @@ export class RoomPageComponent implements OnInit {
           this.commentCounter = this.commentCounter - 1;
         }
       });
+      this.roomService.getStats(this.room.id).subscribe((roomStatistics: RoomStatistics) => {
+        this.roomStatistics = roomStatistics;
+      });
       this.afterRoomLoadHook();
     });
   }

src/app/models/content-group-statistics.ts

+export class ContentGroupStatistics {
+  groupName: string;
+  contentCount: number;
+
+  constructor(
+    groupName: string,
+    contentCount: number
+  ) {
+    this.groupName = groupName;
+    this.contentCount = contentCount
+  }
+}
\ No newline at end of file

src/app/models/room-statistics.ts

+import { ContentGroupStatistics } from './content-group-statistics';
+
+export class RoomStatistics {
+  currentParticipants: number;
+	contentCount: number;
+	unansweredContentCount: number;
+	answerCount: number;
+	unreadAnswerCount: number;
+	commentCount: number;
+	unreadCommentCount: number;
+	groupStats: ContentGroupStatistics[];
+
+  constructor(
+    roomId: string = '',
+    ack: boolean = true) {
+  }
+}

src/app/services/http/room.service.ts

 import { Injectable } from '@angular/core';
 import { Room } from '../../models/room';
+import { RoomStatistics } from '../../models/room-statistics';
 import { RoomJoined } from '../../models/events/room-joined';
 import { RoomCreated } from '../../models/events/room-created';
 import { UserRole } from '../../models/user-roles.enum';
@@ -21,7 +22,8 @@ export class RoomService extends BaseHttpService {
     base: '/api',
     rooms: '/room',
     user: '/user',
-    findRooms: '/find'
+    findRooms: '/find',
+    stats: '/stats'
   };
   private joinDate = new Date(Date.now());
 
@@ -115,6 +117,14 @@ export class RoomService extends BaseHttpService {
     );
   }
 
+  getStats(roomId: string): Observable<RoomStatistics> {
+    const connectionUrl = `${ this.apiUrl.base + this.apiUrl.rooms }/${ roomId }${ this.apiUrl.stats }`;
+    return this.http.get<RoomStatistics>(connectionUrl, httpOptions).pipe(
+      tap(() => ''),
+      catchError(this.handleError<RoomStatistics>('getStats'))
+    );
+  }
+
   parseExtensions(room: Room): Room {
     if (room.extensions) {
       let extensions: TSMap<string, TSMap<string, any>> = new TSMap();