Allow golden image comparison tolerance

[TheMostDiligent]

There is currently a way to specify the threshold when comparing golden images. However, when driver or other software updates, pixel positions may change slightly due to rasterization differences.
To allow tests pass in this case, add option to specify the search radius (radius 1 corresponding to 3x3 search radius should be good option) in most cases.

The comparison should pass if there is a pixel within the threshold in the search area.