Add utils_string and update utils_port header

Add common/include/common/utils/utils_string.h introducing a constexpr common::ConstStrLen for compile-time string length calculation (with include guard and <cstdint> include). Update common/include/common/utils/utils_port.h header comment to correct the @file name and extend the copyright range to 2025-2026.

Author: vanvught

common/include/common/utils/utils_port.h

@@ -1,8 +1,8 @@
 /**
- * @file dmxnode_utils.h
+ * @file utils_port.h
  *
  */
-/* Copyright (C) 2025 by Arjan van Vught mailto:info@gd32-dmx.org
+/* Copyright (C) 2025-2026 by Arjan van Vught mailto:info@gd32-dmx.org
  *
  * Permission is hereby granted, free of charge, to any person obtaining a copy
  * of this software and associated documentation files (the "Software"), to deal

common/include/common/utils/utils_string.h

@@ -0,0 +1,44 @@
+/**
+ * @file utils_string.h
+ *
+ */
+/* Copyright (C) 2026 by Arjan van Vught mailto:info@gd32-dmx.org
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ */
+
+#ifndef COMMON_UTILS_UTILS_STRING_H_
+#define COMMON_UTILS_UTILS_STRING_H_
+
+#include <cstdint>
+
+namespace common
+{
+constexpr uint32_t ConstStrLen(const char* s)
+{
+    uint32_t len = 0;
+    while (s[len] != '\0')
+    {
+        ++len;
+    }
+    return len;
+}
+} // namespace common
+
+#endif // COMMON_UTILS_UTILS_STRING_H_