Move `data/shaders` to `data/shaders/glsl`
Move `data/hlsl` to `data/shaders/hlsl`
Fix up shader paths in the cpp files to point to the new glsl location.
`data/shaders/hlsl/compile.py` still overwrites the glsl .spv files (for
now).
Issue: #723
Test is checking that the format supports being a transfer destination
but is checking the optimalTilingFeatures against an image usage flag
(VK_IMAGE_USAGE_TRANSFER_DST_BIT) instead of a format feature flag
(VK_FORMAT_FEATURE_TRANSFER_DST_BIT) which have different values.
Otherwise the test believes the device does not support the required
format and quits.
