feature: Add Exmaple component together with stubs for component plugin.

source/Navigation/components/CMakeLists.txt

source/Navigation/components/ExampleClient/CMakeLists.txt

source/Navigation/components/ExampleClient/ExampleClient.cpp

source/Navigation/components/ExampleClient/ExampleClient.h

source/Navigation/libraries/client.h

source/Navigation/libraries/client/CMakeLists.txt

source/Navigation/libraries/client/ComponentPlugin.cpp

source/Navigation/libraries/client/ComponentPlugin.h

source/Navigation/libraries/client/Navigator.cpp

source/Navigation/libraries/client/Navigator.h

...ce/Navigation/libraries/client/NavigatorComponentPlugin.h

...raries/trajectory_control/TrajectoryFollowingController.h