[refact] Remove PCL Plugin, add it in external repository
The new repository can be found at https://gitlab.kitware.com/LidarView/plugins/pcl-plugin
System updates will be applied on Apr 24th between 7am and 9am, EST (UTC-05:00). This site will have intermittent downtime during that time.
The new repository can be found at https://gitlab.kitware.com/LidarView/plugins/pcl-plugin