Feature/graph manager (#38)

* Initial changes

* Working state

* Working state

* Working state

* Working state

* Working state

* Working state

* Added graph listener

* Updates

* Testing name demangling

* Graph manager: reworked

* Remove debug trace

* Treat errors when freeing rcutils resources

* Improve logics for discovering entities

* Working state: Micro-ROS graph manager

* Fix micro_ros_graph_info typesupport type name

* Remove double CMakeLists comment

* Remove package.xml commented block

* Add missing include

* Added CI

* Remove GUID_t param from callbacks signature

* Add services names and types to micro-ROS graph topic

* Differenciate between service server and clients

* remove debug traces

Co-authored-by: Pablo Garrido <pablogs9@gmail.com>

micro_ros_msgs/CMakeLists.txt

@@ -0,0 +1,43 @@
+cmake_minimum_required(VERSION 3.5)
+project(micro_ros_msgs)
+
+# Default to C99
+if(NOT CMAKE_C_STANDARD)
+  set(CMAKE_C_STANDARD 99)
+endif()
+
+# Default to C++14
+if(NOT CMAKE_CXX_STANDARD)
+  set(CMAKE_CXX_STANDARD 14)
+endif()
+
+if(CMAKE_COMPILER_IS_GNUCXX OR CMAKE_CXX_COMPILER_ID MATCHES "Clang")
+  add_compile_options(-Wall -Wextra -Wpedantic)
+endif()
+
+# find dependencies
+find_package(ament_cmake REQUIRED)
+find_package(rosidl_default_generators REQUIRED)
+# uncomment the following section in order to fill in
+# further dependencies manually.
+# find_package(<dependency> REQUIRED)
+
+if(BUILD_TESTING)
+  find_package(ament_lint_auto REQUIRED)
+  # the following line skips the linter which checks for copyrights
+  # uncomment the line when a copyright and license is not present in all source files
+  #set(ament_cmake_copyright_FOUND TRUE)
+  # the following line skips cpplint (only works in a git repo)
+  # uncomment the line when this package is not in a git repo
+  #set(ament_cmake_cpplint_FOUND TRUE)
+  ament_lint_auto_find_test_dependencies()
+endif()
+
+rosidl_generate_interfaces(
+  ${PROJECT_NAME}
+  "msg/Graph.msg"
+  "msg/Node.msg"
+  "msg/Entity.msg"
+)
+
+ament_package()