title: DataContext in ContentControl doesnt work
body: <p>I am working with WPF application using MaterialDesign for WPF.
  I have created MainWindow which contains navigation drawer. 
  Here is the XAML of MainWindow:</p>
  
  <pre><code>&lt;materialDesign:DialogHost&gt;
      &lt;materialDesign:DrawerHost IsLeftDrawerOpen="{Binding IsChecked, ElementName=MenuToggleButton}"&gt;
          &lt;materialDesign:DrawerHost.LeftDrawerContent&gt;
          &lt;!--Drawer content--&gt;
          &lt;/materialDesign:DrawerHost.LeftDrawerContent&gt;
  
          &lt;!-- Here is my Content--&gt;
          &lt;ContentControl Name="ContentControl"/&gt;
      &lt;/materialDesign:DrawerHost&gt;
  &lt;/materialDesign:DialogHost&gt;
  </code></pre>
  
  <p>In the ViewModel of MainWindow I added OnMenuItemSelected method which will
  set new content to ContentControl as below:</p>
  
  <pre><code>public void OnMenuItemSelected(object menuItem)
  {
      var itemName = (DrawerMenuItem)menuItem;
      switch (itemName)
      {
          case DrawerMenuItem.Home:
              var window = new ProceduresWindow();
              _contentControl.Content = window.Content;
              break;
          //others
      }
  }
  </code></pre>
  
  <p>In above example when I click Home button in drawer content of ContentControl should be replace with another Window in this example ProcedureWindow. 
  New ProcedureWindow has DataContext set in XAML as below:</p>
  
  <pre><code> &lt;Window.DataContext&gt;
          &lt;windows:ProceduresViewModel&gt;&lt;/windows:ProceduresViewModel&gt;
    &lt;/Window.DataContext&gt;
  </code></pre>
  
  <p>Content is replacing correct but ViewModel is not working. Anyone know how can I solve that?</p>