CmakeLists: Isolate plugin_include_dirs which have specific requirement
In https://gitlab.kitware.com/LidarView/lidarview-core/blob/master/LidarPlugin/CMakeLists.txt#L336
Folders which contain header files that have a specific dependency (eg nanoflann, pcl) should be added to plugin_include_dirs
only if the library they depend on is found