This patch adds initial support for compute shaders to the vulkan backend. As the development is oriented to the test- cases we have the implementation is limited to what is used there. It has been validated that with this patch that the following test cases are running as expected - `GPUVulkanTest.gpu_shader_compute_vbo` - `GPUVulkanTest.gpu_shader_compute_ibo` - `GPUVulkanTest.gpu_shader_compute_ssbo` - `GPUVulkanTest.gpu_storage_buffer_create_update_read` - `GPUVulkanTest.gpu_shader_compute_2d` This patch includes: - Allocating VkBuffer on device. - Uploading data from CPU to VkBuffer. - Binding VkBuffer as SSBO to a compute shader. - Execute compute shader and altering VkBuffer. - Download the VkBuffer to CPU ram. - Validate that it worked. - Use device only vertex buffer as SSBO - Use device only index buffer as SSBO - Use device only image buffers GHOST API has been changed as the original design was created before we even had support for compute shaders in blender. The function `GHOST_getVulkanBackbuffer` has been separated to retrieve the command buffer without a backbuffer (`GHOST_getVulkanCommandBuffer`). In order to do correct command buffer processing we needed access to the queue owned by GHOST. This is returned as part of the `GHOST_getVulkanHandles` function. Open topics (not considered part of this patch) - Memory barriers & command buffer encoding - Indirect compute dispatching - Rest of the test cases - Data conversions when requested data format is different than on device. - GPUVulkanTest.gpu_shader_compute_1d is supported on AMD devices. NVIDIA doesn't seem to support 1d textures. Pull-request: #104518