examples: freemodbus add tcp support for common master/slave iface

Add TCP port files to provide Modbus TCP interface for communication
Add freemodbus add tcp support for common master/slave iface and tcp example based on socket API
The communication between master and slave checked for each example serial_master, serial_slave (use ModbusPoll TCP)
update tcp example according netif changes, fix ci issues
update TCP slave implementation
update example_test.py to to set IP through stdin
update API documentation
event bit instead of semahore to lock communication resource
update default options and master/slave port files

Closes https://github.com/espressif/esp-idf/issues/858
Closes IDF-452

components/freemodbus/tcp_master/modbus_controller/mbc_tcp_master.h

@@ -0,0 +1,43 @@
+/* Copyright 2018 Espressif Systems (Shanghai) PTE LTD
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+*/
+
+//  mbc_tcp_master.h Modbus controller TCP master implementation header file
+
+#ifndef _MODBUS_TCP_CONTROLLER_MASTER
+#define _MODBUS_TCP_CONTROLLER_MASTER
+
+#include <stdint.h>                 // for standard int types definition
+#include <stddef.h>                 // for NULL and std defines
+#include "esp_modbus_common.h"      // for common defines
+
+/* ----------------------- Defines ------------------------------------------*/
+#define MB_INST_MIN_SIZE                    (2) // The minimal size of Modbus registers area in bytes
+#define MB_INST_MAX_SIZE                    (CONFIG_MB_INST_MAX_SIZE) // The maximum size of Modbus area in bytes
+
+#define MB_CONTROLLER_NOTIFY_QUEUE_SIZE     (CONFIG_MB_CONTROLLER_NOTIFY_QUEUE_SIZE) // Number of messages in parameter notification queue
+#define MB_CONTROLLER_NOTIFY_TIMEOUT        (pdMS_TO_TICKS(CONFIG_MB_CONTROLLER_NOTIFY_TIMEOUT)) // notification timeout
+
+/**
+ * @brief Create Modbus Master controller and stack for TCP port
+ *
+ * @param[out] handler handler(pointer) to master data structure
+ * @return
+ *     - ESP_OK   Success
+ *     - ESP_ERR_NO_MEM Parameter error
+ */
+esp_err_t mbc_tcp_master_create(void** handler);
+
+#endif // _MODBUS_TCP_CONTROLLER_SLAVE
+