Support for native-command (#16871)

Support
[sycl_ext_codeplay_enqueue_native_command](https://github.com/intel/llvm/blob/sycl/sycl/doc/extensions/experimental/sycl_ext_codeplay_enqueue_native_command.asciidoc)
with SYCL-Graph for all of L0, CUDA, HIP, and OpenCL backends.

Introduces `interop_handle::ext_oneapi_get_native_graph<backend>()` to
give the user access to the native graph object which native commands
can be appended to. Implemented using new UR command-buffer entry-points
`urCommandBufferAppendNativeCommandExp` and
`urCommandBufferGetNativeHandleExp`.

To use CUDA as an example, code using
`ext_codeplay_enqueue_native_command` eagerly can be updated from:

```cpp
 CGH.ext_codeplay_enqueue_native_command([=](interop_handle IH) {
       auto NativeStream = IH.get_native_queue<cuda>();
       myNativeLibraryCall(NativeStream);
}
```

To

```cpp
CGH.ext_codeplay_enqueue_native_command([=](interop_handle IH) {
     if (IH.ext_oneapi_has_graph())  {
       auto NativeGraph = IH.ext_oneapi_get_native_graph<cuda>();
       auto NativeStream = IH.get_native_queue<cuda>();

       // Start capture stream calls into graph
       cuStreamBeginCaptureToGraph(NativeStream, NativeGraph, nullptr,
                                             nullptr, 0,
                                             CU_STREAM_CAPTURE_MODE_GLOBAL);

       myNativeLibraryCall(NativeStream);

       // Stop capturing stream calls into graph
       cuStreamEndCapture(NativeStream, &NativeGraph);
     } else {
       auto NativeStream = IH.get_native_queue<cuda>();
       myNativeLibraryCall(NativeStream );
    }
}
```

Example of how this integration could work in GROMACS
https://gitlab.com/gromacs/gromacs/-/merge_requests/4954

Author: Ewan Crawford