Fix gazebo_ros/node.hpp not found issue when building uuv_gazebo_ros_plugins

[ashishraste]

Hi Plankton authors,

Thanks for the great work on this project. I'm sure many developers of/using uuv_simulator would find Plankton useful in a ROS2 environment.

Re: this pull request, I noticed the issue attached in the image below when building Plankton via colcon build --packages-up-to plankton. I believe the inclusion of gazebo_dev package dependency alone isn't enough to make CMake/Ament include gazebo_ros headers that the package uuv_gazebo_ros_plugins depends on. This pull-request addresses this issue by including gazebo_ros in the package's CMakeLists.txt, which lets the package to build with appropriate includes from say /opt/ros/foxy/include/gazebo_ros.

Let me know what you think.

System environment details:
OS: Ubuntu 20.04
ROS2 version: Foxy
Gazebo version: 11

Cheers.
Ashish