Bitmap / Remove exception in SetResolution method (#22)

* Avoid raising exception on Bitmap's SetResolution method

Author: damiansalvia

src/Common/Bitmap.cs

@@ -275,7 +275,14 @@ public void SetResolution(float xDpi, float yDpi)
 	{
 		if (xDpi <= 0 || yDpi <= 0) 
 			throw new ArgumentOutOfRangeException("DPI values must be greater than zero.");
-		throw new NotSupportedException("not supported by skia"); // SOURCE: https://issues.skia.org/issues/40043604
+		if (float.IsNaN(xDpi) || float.IsInfinity(xDpi))
+			throw new ArgumentException($"DPI values must be numbers but {xDpi} was given.", nameof(xDpi));
+		if (float.IsNaN(yDpi) || float.IsInfinity(yDpi))
+			throw new ArgumentException($"DPI values must be numbers but {yDpi} was given.", nameof(yDpi));
+		HorizontalResolution = xDpi;
+		VerticalResolution = yDpi;
+		// NOTE: HorizontalResolution and VerticalResolution properties assignment has no effect 
+		// on Save because Skia does not support it (source: https://issues.skia.org/issues/40043604)
 	}
 
 	/// <summary>