Add tests for VK_EXT_blend_operation_advanced

Add tests for VK_EXT_blend_operation_advanced

There at three types of tests:

* Ops: they check that all the defined operations work
for a different set of source and destination colors, iterating over
(non)premultiplied colors and uncorrelate/disjoint/conjoint alpha
values.  The tests run on different number of color attachment as well.

* Independent: it checks that color attachments with different depth
operations do not affect the others.

* Coherent: it checks if (non)coherent blend operations work as
expected. It creates two pipelines with 2 different advanced blend ops,
first draw clears the pixel with a specified destination color and do
the blending; the second draw reuses the result of the first one as
destination color and do blending on top. In the case of noncoherent
blending, it adds a memory dependency between both advanced blend
operations.

Added tests:

   dEQP-VK.pipeline.blend_operation_advanced.*

Components: Vulkan
VK-GL-CTS issue: 1673

Change-Id: I4417e6a22e0c2882849f8bf59233c266c60e45c6