Public interface leaks ifm3d headers

[theseankelly]

ifm3d library headers are unnecessarily exposed to clients through camera_node.hpp here:

ifm3d-ros2/include/ifm3d_ros2/camera_node.hpp

Line 39 in c281b5e

#include <ifm3d/camera.h>

This requires client packages to find_package(ifm3d) and target_link_libraries(... ifm3d::camera ifm3d::framegrabber ifm3d::image) or else ensure ifm3d is on the include path when building packages which consume ifm3d-ros2.

The implementation details (the ifm3d bits) should be hidden via pImpl to keep the public interface ROS-only.