Add copy tests for wide and tall images

Add copy tests for wide and tall images

Test image copying on wide and tall images on YCbCr and
non-YCbCr formats with the following image dimensions:
-Wide: large pot x small pot
-Wide: large pot x small npot
-Tall: small pot x large pot
-Tall: small npot x large pot

This CL also changes the initialization of the source image
in image_to_image copy tests to gradient from the current
solid red color to detect that the copy regions are handled
correctly.

Affects:

dEQP-VK.api.copy_and_blit.*.image_to_image.*

New tests:

dEQP-VK.api.copy_and_blit.*.image_to_image.dimensions.*
dEQP-VK.ycbcr.copy_dimensions.*

Components: Vulkan

VK-GL-CTS issue: 1724

Change-Id: I9d61a782ba5a07b6cd9c47e158d441cf935b5ac7