Use nvtx3 includes in string examples. (rapidsai#13165)

This PR updates libcudf string examples to use `<nvtx3/nvToolsExt.h>`. This ensures we fetch the header-only NVTX v3. See NVTX docs for more information: https://nvidia.github.io/NVTX/#c-and-c

Authors:
  - Bradley Dice (https://github.com/bdice)

Approvers:
  - David Wendt (https://github.com/davidwendt)
  - Nghia Truong (https://github.com/ttnghia)
  - Vyas Ramasubramani (https://github.com/vyasr)

URL: rapidsai#13165

cpp/examples/strings/custom_optimized.cu

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2022, NVIDIA CORPORATION.
+ * Copyright (c) 2022-2023, NVIDIA CORPORATION.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -26,7 +26,7 @@
 #include <thrust/scan.h>
 
 #include <cuda_runtime.h>
-#include <nvToolsExt.h>
+#include <nvtx3/nvToolsExt.h>
 
 /**
  * @brief Computes the size of each output row

cpp/examples/strings/custom_prealloc.cu

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2022, NVIDIA CORPORATION.
+ * Copyright (c) 2022-2023, NVIDIA CORPORATION.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -23,7 +23,7 @@
 #include <rmm/device_uvector.hpp>
 
 #include <cuda_runtime.h>
-#include <nvToolsExt.h>
+#include <nvtx3/nvToolsExt.h>
 
 /**
  * @brief Builds the output for each row

cpp/examples/strings/custom_with_malloc.cu

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2022, NVIDIA CORPORATION.
+ * Copyright (c) 2022-2023, NVIDIA CORPORATION.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -23,7 +23,7 @@
 #include <rmm/device_uvector.hpp>
 
 #include <cuda_runtime.h>
-#include <nvToolsExt.h>
+#include <nvtx3/nvToolsExt.h>
 
 /**
  * @brief Reserve CUDA malloc heap size

cpp/examples/strings/libcudf_apis.cpp

@@ -25,7 +25,7 @@
 #include <cudf/strings/strings_column_view.hpp>
 
 #include <cuda_runtime.h>
-#include <nvToolsExt.h>
+#include <nvtx3/nvToolsExt.h>
 
 /**
  * @brief Redacts each name per the corresponding visibility entry