Restructure platform directory (#382)

This updates the platform and logging directory and moves it to the following places:
FreeRTOS\FreeRTOS-Plus\Source\Utilities
FreeRTOS\FreeRTOS-Plus\Source\Application-Protocols\network_transport\freertos_plus_tcp

Project files are updated to follow suite. All updated demos are tested to work as expected.

FreeRTOS-Plus/Source/Utilities/mbedtls_freertos/mbedtls_error.h

@@ -0,0 +1,63 @@
+/*
+ * FreeRTOS Error Code Stringification utilities for mbed TLS v2.16.0
+ * Copyright (C) 2020 Amazon.com, Inc. or its affiliates.  All Rights Reserved.
+ *
+ * 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.
+ */
+
+/**
+ * @file mbedtls_error.h
+ * @brief Stringification utilities for high-level and low-level codes of mbed TLS.
+ */
+
+#ifndef MBEDTLS_ERROR_H_
+    #define MBEDTLS_ERROR_H_
+
+    #include <stdint.h>
+
+    #ifdef __cplusplus
+        extern "C" {
+    #endif
+
+/**
+ * @brief Translate an mbed TLS high level code into its string representation.
+ *        Result includes a terminating null byte.
+ *
+ * @param errnum The error code containing the high-level code.
+ * @return The string representation if high-level code is present; otherwise NULL.
+ *
+ * @warning The string returned by this function must never be modified.
+ */
+    const char * mbedtls_strerror_highlevel( int32_t errnum );
+
+/**
+ * @brief Translate an mbed TLS low level code into its string representation,
+ *        Result includes a terminating null byte.
+ *
+ * @param errnum The error code containing the low-level code.
+ * @return The string representation if low-level code is present; otherwise NULL.
+ *
+ * @warning The string returned by this function must never be modified.
+ */
+    const char * mbedtls_strerror_lowlevel( int32_t errnum );
+
+    #ifdef __cplusplus
+}
+    #endif
+
+#endif /* ifndef MBEDTLS_ERROR_H_ */