feat: (Messaging) TypeScript def

- fix TypeScript definition for "subscribe" method of Messaging Service

Author: Valodya

libs/backendless.d.ts

@@ -620,9 +620,9 @@ declare module __Backendless {
         restUrl:string;
         channelProperties:Object;
 
-        subscribe(channelName:string, subscriptionCallback:() => void, subscriptionOptions:Backendless.SubscriptionOptions):Backendless.SubscriptionI;
-        subscribe(channelName:string, subscriptionCallback:() => void, subscriptionOptions:Backendless.SubscriptionOptions, async:Backendless.Async):XMLHttpRequest;
-        subscribe<Promise>(channelName:string, subscriptionCallback:() => void, subscriptionOptions:Backendless.SubscriptionOptions):Promise;
+        subscribe(channelName:string, subscriptionCallback:(data:Object) => void, subscriptionOptions:Backendless.SubscriptionOptions):Backendless.SubscriptionI;
+        subscribe(channelName:string, subscriptionCallback:(data:Object) => void, subscriptionOptions:Backendless.SubscriptionOptions, async:Backendless.Async):XMLHttpRequest;
+        subscribe<Promise>(channelName:string, subscriptionCallback:(data:Object) => void, subscriptionOptions:Backendless.SubscriptionOptions):Promise;
 
         publish(channelName:string, message:string|Object, publishOptions:Backendless.PublishOptions, deliveryOptions:Backendless.DeliveryOptions):Object;
         publish(channelName:string, message:string|Object, publishOptions:Backendless.PublishOptions, deliveryOptions:Backendless.DeliveryOptions, async:Backendless.Async):XMLHttpRequest;

tests/tsd.ts

@@ -644,7 +644,8 @@ function testMessaging() {
     var deliveryOptions:Backendless.DeliveryOptions = new Backendless.DeliveryOptions();
     var subscription:Backendless.SubscriptionI;
     var subscriptionOptions:Backendless.SubscriptionOptions = new Backendless.SubscriptionOptions();
-    var subscriptionCallback = function ():void {
+    var subscriptionCallback = function (data:Object) {
+        var messagesArray:Array<String> = data["messages"];
     };
     var async:Backendless.Async = new Backendless.Async(function (data:Object) {
     });