Do the browser default behavior when clicking on a label in a toolbar.
Do the browser default behavior when clicking on a label in a toolbar.

We were too aggressive about activating the parent widget when getting a click in the toolbar. If we have a label for a control, clicking on the label by default focuses the control, which is what we want, but we were often wresting focus away from the control when we called the activate function.
jupyter/jupyterlab,jupyter/jupyterlab,jupyter/jupyterlab,jupyter/jupyterlab,jupyter/jupyterlab