[util] Add numpy file reader

In deep learning data feeding, there are often tasks that involve reading and processing numpy (.npy) files.

Therefore, it would be much more convenient to develop by entering the file name and returning the data in a vector instead of manually writing code to read it every time.

Function Signature
```
void read_npy_file(const char *file_path, std::vector<int> &dims,
                   std::vector<float> &values);
```

**Self evaluation:**
1. Build test:	 [X]Passed [ ]Failed [ ]Skipped
2. Run test:	 [X]Passed [ ]Failed [ ]Skipped

Signed-off-by: Donghak PARK <[email protected]>

Applications/utils/meson.build

@@ -1,2 +1,3 @@
 subdir('jni')
 subdir('datagen/cifar')
+subdir('npy_reader')

Applications/utils/npy_reader/meson.build

@@ -0,0 +1,2 @@
+npy_path = meson.current_source_dir()
+npy_include_dir = include_directories('.')

Applications/utils/npy_reader/npy_reader.cpp

@@ -0,0 +1,119 @@
+// SPDX-License-Identifier: Apache-2.0
+/**
+ * Copyright (C) 2024 Donghak Park <[email protected]>
+ *
+ * @file   npy_reader.cpp
+ * @date   28 Feb 2024
+ * @brief  reader for npy file
+ * @see    https://github.com/nnstreamer/nntrainer
+ * @author Donghak Park <[email protected]>
+ * @bug    No known bugs except for NYI items
+ */
+
+#include "npy_reader.h"
+
+#include <assert.h>
+#include <cstring>
+#include <iostream>
+#include <random>
+#include <string>
+#include <vector>
+
+namespace nntrainer::util {
+namespace {
+/**
+ * @brief read numpy file from file_path
+ * 
+ * @param file_path file_path that want to read
+ * @param dims data shape
+ * @param values return value that contain npy's contents
+ */
+void read_npy_file(const char *file_path, std::vector<int> &dims,
+                   std::vector<float> &values) {
+  FILE *file = fopen(file_path, "rb");
+
+  char magic[7] = {};
+  fread(magic, 6, 1, file);
+  assert(strcmp(magic, "\x93NUMPY") == 0);
+
+  char major = 0;
+  fread(&major, 1, 1, file);
+
+  char minor = 0;
+  fread(&minor, 1, 1, file);
+
+  uint16_t header_len;
+  fread(&header_len, 2, 1, file);
+
+  char *header = (char *)malloc(header_len);
+  fread(header, header_len, 1, file);
+
+  char *header_pos = header;
+  assert(*header_pos == '{');
+  ++header_pos;
+  char buffer[1024];
+  int buffer_pos = 0;
+
+  while (*header_pos != '}') {
+    if (*header_pos == '\'') {
+      ++header_pos;
+      while (*header_pos != '\'') {
+        buffer[buffer_pos++] = *header_pos++;
+      }
+
+      buffer[buffer_pos++] = '\0';
+
+      if (strcmp(buffer, "shape") == 0) {
+        header_pos += 3;
+        assert(*header_pos == '(');
+        ++header_pos;
+
+        while (*header_pos != ')') {
+          buffer_pos = 0;
+          while (*header_pos != ',' && *header_pos != ')') {
+            buffer[buffer_pos++] = *header_pos++;
+          }
+
+          int mul = 1;
+          int value = 0;
+          for (int i = buffer_pos - 1; i >= 0; --i) {
+            value += static_cast<int>(buffer[i] - '0') * mul;
+            mul *= 10;
+          }
+          dims.push_back(value);
+
+          if (*header_pos != ')') {
+            header_pos += 2;
+          }
+        }
+
+        header_pos += 3;
+      } else {
+        while (*header_pos != ',') {
+          ++header_pos;
+        }
+        header_pos += 2;
+        buffer_pos = 0;
+      }
+    }
+  }
+
+  free(header);
+  header = nullptr;
+
+  int total_entries = 1;
+  for (int i = 0; i < dims.size(); ++i) {
+    total_entries *= dims[i];
+  }
+
+  for (int i = 0; i < total_entries; ++i) {
+    float value;
+    fread(&value, 4, 1, file);
+    values.push_back(value);
+  }
+
+  fclose(file);
+}
+} // namespace
+
+} // namespace nntrainer::util

Applications/utils/npy_reader/npy_reader.h

@@ -0,0 +1,31 @@
+// SPDX-License-Identifier: Apache-2.0
+/**
+ * Copyright (C) 2024 Donghak Park <[email protected]>
+ *
+ * @file   npy_reader.h
+ * @date   28 Feb 2024
+ * @brief  reader for npy file
+ * @see    https://github.com/nnstreamer/nntrainer
+ * @author Donghak Park <[email protected]>
+ * @bug    No known bugs except for NYI items
+ */
+
+#ifndef NPY_READER_H_
+#define NPY_READER_H_
+
+#include <vector>
+
+namespace nntrainer::util {
+/**
+ * @brief read numpy file from file_path
+ * 
+ * @param file_path file_path that want to read
+ * @param dims data shape
+ * @param values return value that contain npy's contents
+ */
+void read_npy_file(const char *file_path, std::vector<int> &dims,
+                   std::vector<float> &values);
+
+} // namespace nntrainer::util
+
+#endif // NPY_READER_H_