chore: moar testing

The story so far: `Given_ContentDialog.When_SimpleContentDialog()` is
failing, e.g.

	ImageAssert.AreEqual @ line 45
	pixelTolerance: Color Cumulative tolerance of 20 | Location PerRange tolerance of 0,0 pixels.
	expected: When_Dialog_Before (When_SimpleContentDialogSimpleDialogCodebehindButton_0_False_When_Dialog_Before.png {Width=1024, Height=768}) in {X=0,Y=0,Width=1024,Height=768}
	actual  : When_Dialog_Closed (When_SimpleContentDialogSimpleDialogCodebehindButton_0_False_When_Dialog_Closed.png {Width=1024, Height=768}) in {X=0,Y=0,Width=1024,Height=768}

	When_Dialog_Before:
	564,688: expected: [564,688] FFF4F4EA | actual: [564,688] FFEDEDF3
	a tolerance of 23 [Cumulative] would be required for this test to pass.
	Current: Color Cumulative tolerance of 20 | Location PerRange tolerance of 0,0 pixels.

	With expectedRect:
	{X=0,Y=0,Width=2147483647,Height=2147483647}
	With actualRect:
	{X=0,Y=0,Width=2147483647,Height=2147483647}
	With expectedToActualScale:
	1

With local manual testing, our conjecture is that the color change is
due to the "pointer over" effect:

 1. When taking the "Before" picture, the **Content Dialogs** button
    is *yellow*, as per 08accad.

 2. Meanwhile, the "After" pictures are *not* yellow.

Thus, we believe that:

 1. App is launched

 2. **Test Harness** > **Dialogs** is clicked.

 3. **Content Dialogs** (bottom of the screen* is clicked.)

   This is the effective beginning of the `When_SimpleContentDialog()`
   test.

 4. The "mouse" cursor *remains* over **Content Dialogs** at this
    point, conferring the "pointer over" effect.

 5. The "When_Dialog_Before" screenshot is taken.

 6. The unit test does "stuff"

 7. The "When_Dialog_Closed" screenshot is taken.

 8. (5) and (7) are compared.  However, as the mouse cursor *isn't*
    over **Content Dialog** when (7) occurs, the images *differ*.

As an attempted workaround, "move the mouse" between (3) and (4)
by "tapping" the **Message Dialog Tests** (`DialogsContentDialogsPage`)
*header*.  This isn't a button, clicking it does *nothing*, but
clicking it should "move" the mouse away from `ContentDialogsButton`.
This should improve the "Before" image, fixing the image comparison.

Author: jonpryor

testing/TestHarness/TestHarness.UITest/Ext/Navigation/Dialogs/Given_ContentDialog.cs

@@ -13,6 +13,7 @@ public async Task When_SimpleContentDialog(string dialogButton, int delayInSecon
 		App.WaitThenTap("ContentDialogsButton");
 
 		App.WaitElement("DialogsContentDialogsPage");
+		App.Tap("DialogsContentDialogsPage");
 		App.Wait(TimeSpan.FromSeconds(1));
 		var screenBefore = TakeScreenshot("When_Dialog_Before");
 		App.FastTap(dialogButton);