Add fp16 float control tests without 16bit_storage requirement

Add fp16 float control tests without 16bit_storage requirement

This CL adds new tests that don't require VK_KHR_16bit_storage
extension support to read float16 inputs or write float16 outputs.

It required to modify the fp16 output buffer size to hold an
unsigned 32-bits integer, whose 16 MSB are going to be unused
by the verification function but are needed to avoid requiring
VK_KHR_16bit_storage extension support.

A new userData member was added to the Resource class in order to
facilitate the selection of the verification function when we have
multiple outputs with different sizes (see checkMixedFloats()
function in vktSpvAsmFloatControlsTests.cpp).

Added tests:

   dEQP-VK.spirv_assembly.instruction.*.float_controls.*nostorage*

Modified tests:

   dEQP-VK.spirv_assembly.instruction.*.float_controls.*

Components: Vulkan
VK-GL-CTS issue: 1877

Signed-off-by: Samuel Iglesias Gonsálvez <siglesias@igalia.com>
Change-Id: Ice7a6129ee7cfe8a8813115530584bb6dde607ba