computecloth: Optimize barriers and add compute queue double buffering

[SRSaunders]

This PR addresses the concerns raised in #1097:

1. Optimizes compute-to-compute barriers so that write-to-read memory barriers are only applied to the buffer being written to. The read buffer does not require a memory barrier - this PR eliminates that unnecessary barrier.
2. Adjusts the graphics-to-compute barrier to use VK_PIPELINE_STAGE_COLOR_ATTACHMENT_OUTPUT_BIT instead of VK_PIPELINE_STAGE_VERTEX_INPUT_BIT, with access mask now set to VK_ACCESS_COLOR_ATTACHMENT_WRITE_BIT. The previous settings seemed to work, but I believe these are more correct.
3. Adds double-buffering capability for the compute queue with significantly increased performance (~50% greater on Windows, >100% greater on Linux, no change on macOS). There have always been 2 compute command buffers created but only 1 has been used up to this point. This adds semaphore sync support for using the 2 compute command buffers which results in parallel execution of the compute and graphics queues. A new COMPUTE_CMD_BUFFERS define is available to switch between double and single buffered operation. Default setting is COMPUTE_CMD_BUFFERS = 2 for double buffering, but can be set = 1 for experimentation. See the following AMD GPU Profiler traces for insight.

Changes tested on Windows 10, Manjaro Linux, macOS Ventura 13.6.6 with no validation errors or warnings.

Single buffering / Serial queue operation (COMPUTE_CMD_BUFFERS = 1):

Double buffering / Parallel queue operation (COMPUTE_CMD_BUFFERS = 2):