examples: Add common linux component tapif_io

That can be used with linux target on lwip to pass packets from lwip to
linux host networking stack, e.g. routing the trafic to internet.

examples/common_components/protocol_examples_tapif_io/include/protocol_examples_common.h

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+/*
+ * SPDX-FileCopyrightText: 2022-2023 Espressif Systems (Shanghai) CO LTD
+ *
+ * SPDX-License-Identifier: Unlicense OR CC0-1.0
+ */
+/* Common functions for protocol examples, to establish tap interface connection
+ * For linux target
+
+   This example code is in the Public Domain (or CC0 licensed, at your option.)
+
+   Unless required by applicable law or agreed to in writing, this
+   software is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR
+   CONDITIONS OF ANY KIND, either express or implied.
+ */
+#pragma once
+#include "esp_err.h"
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+/**
+ * @brief Configure and connect, wait for IP
+ *
+ * @return ESP_OK on successful connection
+ */
+esp_err_t example_connect(void);
+
+
+#ifdef __cplusplus
+}
+#endif

examples/common_components/protocol_examples_tapif_io/include/tapio.h

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+/*
+ * SPDX-FileCopyrightText: 2022-2023 Espressif Systems (Shanghai) CO LTD
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ */
+#pragma once
+#include "esp_err.h"
+#include "esp_netif.h"
+
+/**
+ * @brief Creates tapio layer as a driver interface to esp-netif
+ *
+ * @warning Implemented as singleton, can use only one tapio in the system!
+ *
+ * @return pointer to the tapio driver handle
+ */
+void *tapio_create(void);
+
+/**
+ * @brief esp-netif driver I/O output path
+ *
+ * @param h Driver's handle
+ * @param buffer Data to output
+ * @param len Data size
+ * @return ESP_OK on success
+ */
+esp_err_t tapio_output(void *h, void *buffer, size_t len);