Add simulation mode for gnss localizer
Added a "special plane" for GNSS coordinate conversion with coordinates at (0, 0) lat/lon.
For GNSS localization, Autoware currently parses the /nmea_sentence, extracts the latitude and longitude and converts them to coordinates in the Japanese rectangular coordinate system. There are 19 planes to chose from for the origin of the coordinate system but they would all chose an origin at or near Japan. Because of this gnss_localizer can only be used to localize on maps that are near japan. This merge request provides a work around for using Autoware at coordinates outside of Japan, by simply offsetting to the origin of the special plane (plane 0) which is at (0, 0) lat/lon. This is especially useful for using Autoware in simulation.
Adding an additional plane will not impact the functionality of the gnss_localizer for Japanese coordinates. Since the planes are numbered from 1-19 in the Japanese system, the number 0 has been chosen for the special plane.
Alternatives would be to convert lat/lon to a different coordinate system that would be supported outside of Japan. The present implementation would provide a simple work-around to be used until such a coordinate system is adopted by Autoware (if on the road map).