Refactor and fix error hydration message socket io

- Position message send will be on format :
message :
                    userId : user identification
                    roomId: room identification
                    position: position of user in map
                        x: user x position on map
                        y: user y position on map
 - Create Point object and interface to have position x and y of user in map.

back/src/Model/Websocket/PointInterface.ts

@@ -0,0 +1,5 @@
+export interface PointInterface {
+    x: number;
+    y: number;
+    toJson() : object;
+}