fix(esp_mqtt_cxx): reference protocol_examples_common from IDF

This makes the example project usable from the component registry

components/esp_mqtt_cxx/examples/ssl/CMakeLists.txt

@@ -2,11 +2,6 @@
 # CMakeLists in this exact order for cmake to work correctly
 cmake_minimum_required(VERSION 3.16)
 
-# (Not part of the boilerplate) This example uses an extra component for common
-# functions such as Wi-Fi and Ethernet connection.
-set(EXTRA_COMPONENT_DIRS
-    "../../../../common_components/protocol_examples_common")
-
 include($ENV{IDF_PATH}/tools/cmake/project.cmake)
 project(mqtt_ssl_cxx)
 

components/esp_mqtt_cxx/examples/ssl/main/idf_component.yml

@@ -2,5 +2,7 @@ dependencies:
   ## Required IDF version
   idf: ">=5.0"
   espressif/esp_mqtt_cxx:
-    version: "^0.1.0"
+    version: "~0"
     override_path: "../../../"
+  protocol_examples_common:
+    path: ${IDF_PATH}/examples/common_components/protocol_examples_common

components/esp_mqtt_cxx/examples/tcp/CMakeLists.txt

@@ -2,10 +2,5 @@
 # in this exact order for cmake to work correctly
 cmake_minimum_required(VERSION 3.16)
 
-# (Not part of the boilerplate)
-# This example uses an extra component for common functions such as Wi-Fi and Ethernet connection.
-set(EXTRA_COMPONENT_DIRS
-    "../../../../common_components/protocol_examples_common")
-
 include($ENV{IDF_PATH}/tools/cmake/project.cmake)
 project(mqtt_tcp_cxx)

components/esp_mqtt_cxx/examples/tcp/main/idf_component.yml

@@ -2,5 +2,7 @@ dependencies:
   ## Required IDF version
   idf: ">=5.0"
   espressif/esp_mqtt_cxx:
-    version: "^0.1.0"
+    version: "~0"
     override_path: "../../../"
+  protocol_examples_common:
+    path: ${IDF_PATH}/examples/common_components/protocol_examples_common