Fix nuxeo dialog width

In some cases, the nuxeo-dialog width does not adapt to its content and we end up with a horizontal scrolling bar.

For example, when editing a multicomplex document defined in https://github.com/nuxeo/nuxeo-web-ui-itests we observe a strange nuxeo dialog resizing where the width is bigger when the window is half its normal size than in full screen. See attached screen capture.