Fix QCamera viewfinder capabilities functions..

- Filtering the results for a specific pixel aspect ratio would return
  wrong values.
- Correctly sort the frame rate ranges returned by
  supportedViewfinderFrameRateRanges().

Added missing auto-tests for all viewfinder capabilities functions.

Change-Id: Idfb40d4139cc48a5996ce2ddd98131a2f5be76bb
Reviewed-by: Christian Stromme <christian.stromme@theqtcompany.com>

src/multimedia/camera/qcameraviewfindersettings.cpp

@@ -50,8 +50,7 @@ public:
         isNull(true),
         minimumFrameRate(0.0),
         maximumFrameRate(0.0),
-        pixelFormat(QVideoFrame::Format_Invalid),
-        pixelAspectRatio(1, 1)
+        pixelFormat(QVideoFrame::Format_Invalid)
     {
     }