title: PyQT5 QFileDialog window title not showing on mac
body: <p>I made a PyQt5 application on Windows and now I want to use the application on a Mac. The app prompts the user to select a couple different files. I used the title of the QFileDialog window to let the user know which files like so:</p>
  <pre><code>    instrument_file_raw=QFileDialog().getOpenFileName(self, &quot;Select Instrument File&quot;,&quot;&quot;,&quot;Excel (*.xlsx)&quot;)
      instrument_file_raw=str(instrument_file_raw[0])
      
      if instrument_file_raw==&quot;&quot;:
          error_dialog = QErrorMessage(self)
          error_dialog.showMessage('No filename entered')
          return
      
      run_list_file=QFileDialog().getOpenFileName(self, &quot;Select Run List File&quot;,&quot;&quot;,&quot;Excel (*.xlsx)&quot;)
      run_list_file=str(run_list_file[0])
      
      if run_list_file==&quot;&quot;:
          error_dialog = QErrorMessage(self)
          error_dialog.showMessage('No filename entered')
          return
  </code></pre>
  <p>However when I run the same code on Mac there is no window title shown when the file explorer opens. Even if I manually set the window title by</p>
  <pre><code>instrument_file_window=QFileDialog()
  instrument_file_window.setWindowTitle(&quot;Select Instrument File&quot;)
  instrument_file_raw=instrument_file_window.getOpenFileName(self,&quot;Select Instrument File&quot;,&quot;&quot;,&quot;Excel (*.xlsx)&quot;) 
  </code></pre>
  <p>Is there a way to show the window title on Mac? How can I indicate to the user what to input?</p>