Fix pop-up blocking for workflows

When using workflows such as the CreateDSL template, the automatic opening of a new window can sometimes be blocked as a pop-up (on Chrome, untested on Firefox).

The issue is that the window is opened without a direct user action, such as a click: https://stackoverflow.com/questions/2587677/avoid-browser-popup-blockers

Due to the messages passed between the MT server, the AToMPM server, and the client, the workflow interaction triggers the popup detection.

Reproduce the CreateDSL workflow in Chrome and trace the messages passed between the MT server, AToMPM server, and client. The fix is complete when the workflow can open its new window without being blocked as a pop-up.

Written by the indexing model from the issue text.