[EXP][Command-Buffer] Add kernel command update

This change introduces a new API that allows the kernel commands of a command-buffer to be updated
with a new configuration. For example, modified arguments or ND-Range.

The new API is defined in the following files and then source generated using scripts, so reviewers should look at:
* `scripts/core/EXP-COMMAND-BUFFER.rst`
* `scripts/core/exp-command-buffer.yml`

See [cl_khr_command_buffer_mutable_dispatch](https://registry.khronos.org/OpenCL/specs/3.0-unified/html/OpenCL_Ext.html#cl_khr_command_buffer_mutable_dispatch) as prior art. The differences between the proposed API and the above are:

* Only the append kernel entry-point returns a command handle. I imagine this will be changed in future to enable other commands to do update.
* USM,  buffer, and scalar arguments can be updated, there is not equivalent update struct for `urKernelSetArgLocal` or `urKernelSetArgSampler`
* There is no granularity of optional support for update, an implementer must either implement all the ways to update a kernel configuration, or none of them.

The CUDA adapter is the only adapter that currently implements this new feature, other adapters don't report support. This is because CUDA is already an adapter supported by UR command-buffers, and the CUDA API for updating nodes already exists as a non-optional feature.

Reviewers should review the changes in `source/adapters/cuda/` to evaluate this,

CTS tests are written to verify implementation, as there is not yet a DPC++ feature with testing to stress the code path (see reble/llvm#340 for how that feature could look).

A new test directory has been created to test the command-buffer experimental feature, `test/conformance/exp_command_buffer`, which contains tests to stress using the feature defined by this extension so that it has code coverage. Reviewers should look at the new tests added here, and new device kernels in `test/conformance/device_code` to evaluate these changes.

Author: EwanC

include/ur_api.h

@@ -1853,7 +1853,8 @@ typedef ur_result_t(UR_APICALL *ur_pfnCommandBufferAppendKernelLaunchExp_t)(
     const size_t *,
     uint32_t,
     const ur_exp_command_buffer_sync_point_t *,
-    ur_exp_command_buffer_sync_point_t *);
+    ur_exp_command_buffer_sync_point_t *,
+    ur_exp_command_buffer_command_handle_t *);
 
 ///////////////////////////////////////////////////////////////////////////////
 /// @brief Function-pointer for urCommandBufferAppendUSMMemcpyExp
@@ -2010,6 +2011,12 @@ typedef ur_result_t(UR_APICALL *ur_pfnCommandBufferEnqueueExp_t)(
     const ur_event_handle_t *,
     ur_event_handle_t *);
 
+///////////////////////////////////////////////////////////////////////////////
+/// @brief Function-pointer for urCommandBufferUpdateKernelLaunchExp
+typedef ur_result_t(UR_APICALL *ur_pfnCommandBufferUpdateKernelLaunchExp_t)(
+    ur_exp_command_buffer_command_handle_t,
+    const ur_exp_command_buffer_update_kernel_launch_desc_t *);
+
 ///////////////////////////////////////////////////////////////////////////////
 /// @brief Table of CommandBufferExp functions pointers
 typedef struct ur_command_buffer_exp_dditable_t {
@@ -2030,6 +2037,7 @@ typedef struct ur_command_buffer_exp_dditable_t {
     ur_pfnCommandBufferAppendUSMPrefetchExp_t pfnAppendUSMPrefetchExp;
     ur_pfnCommandBufferAppendUSMAdviseExp_t pfnAppendUSMAdviseExp;
     ur_pfnCommandBufferEnqueueExp_t pfnEnqueueExp;
+    ur_pfnCommandBufferUpdateKernelLaunchExp_t pfnUpdateKernelLaunchExp;
 } ur_command_buffer_exp_dditable_t;
 
 ///////////////////////////////////////////////////////////////////////////////