fix(VirtualStream): Fix backpressure handling in VirtualStream workOnQueue method

ts/classes.virtualstream.ts

@@ -143,10 +143,17 @@ export class VirtualStream<T = Uint8Array> implements plugins.typedRequestInterf
 
   constructor() {}
 
+  workingDeferred: plugins.smartpromise.Deferred<void>;
+
   /**
    * takes care of sending 
    */
   private async workOnQueue() {
+    if (this.workingDeferred) {
+      return this.workingDeferred.promise;
+    } else {
+      this.workingDeferred = plugins.smartpromise.defer();
+    }
     if(this.side === 'requesting') {
       let thisSideIsBackpressured = !this.receiveBackpressuredArray.checkSpaceAvailable();
       let otherSideHasNext = false;
@@ -219,6 +226,8 @@ export class VirtualStream<T = Uint8Array> implements plugins.typedRequestInterf
       }
 
     }
+    this.workingDeferred.resolve();
+    this.workingDeferred = null;
   }
 
   /**