message: Round our Maximize button to match ControlsV2 styles
  Just look at the screenshot. Above is before, below is now.
  ![image](https://user-images.githubusercontent.com/18356694/157717931-f3e3167e-0234-425a-a8eb-02303f386dc6.png)
  These paths were taken straight from WinUI versions of these icons, thanks for the alley oop.
  * [x] Closes
  * [x] Tested manually by _lookin at it_
diff: Click="_MaximizeClick"
  Style="{StaticResource CaptionButton}">
  <Button.Resources>
  + <!-- These paths are complicated, but taken directly from WinUI's WindowCaptionButton paths. -->
  <ResourceDictionary>
  - <x:String x:Key="CaptionButtonPath">M 0 0 H 10 V 10 H 0 V 0</x:String>
  - <x:String x:Key="CaptionButtonPathWindowMaximized">M 0 2 h 8 v 8 h -8 v -8 M 2 2 v -2 h 8 v 8 h -2</x:String>
  + <x:String x:Key="CaptionButtonPath">M 1.516 -0.001 L 7.451 0.009 C 8.751 0.019 9 1 8.981 1.477 L 9.002 7.558 M 9.002 7.547 C 8.929 8.669 8 9 7.43 9.015 L 1.464 9.005 C 0.374 8.973 0 8 -0.004 7.484 L -0.004 1.477 C 0 1 0.415 0.009 1.527 -0.001</x:String>
  + <x:String x:Key="CaptionButtonPathWindowMaximized">M 1.516 -0.001 L 7.451 0.009 C 8.751 0.019 9 1 8.981 1.477 L 9.002 7.558 M 11 6 L 11 2 C 11 0 10 -2 8.011 -1.946 L 7.06 -1.969 L 3 -2 M 9.002 7.547 C 8.929 8.669 8 9 7.43 9.015 L 1.464 9.005 C 0.374 8.973 0 8 -0.004 7.484 L -0.004 1.477 C 0 1 0.415 0.009 1.527 -0.001</x:String>
  </ResourceDictionary>
  </Button.Resources>
  <ToolTipService.ToolTip>
  