PySide tools on Windows sometimes fall back to dialog/popup for stdout

Relates loosely to https://github.com/seanwu1105/vscode-qt-for-python/issues/324

When running on Windows, some PySide tools, specifically `qmlls`, when launched from a non-console application will fall back to displaying stdout as a dialog popup.

This seems to be caused by line 60 in pyside_tools.py,

returncode = subprocess.call(cmd).

If this line is changed to

{{returncode = subprocess.call(cmd, stdout=sys.stdout, stderr=sys.stderr) }}

then the dialog popup is suppressed.

I'm aware this may be intended behavior, but I thought it worth mentioning just in case.