DNM: Fixed failing visualization manager test cases

Details coming soon to the GitHub near you...
In N-Unit run, this method is being called on the main thread of the test case. Here we generalize ```Render Complete``` handler to see if the calling thread is the same as the main UI thread. If they are the same, then a direct call to ```getBranchVisualization``` can be made, otherwise it has to be dispatched to the main thread for execution at a later time.