feat(editor): the terrain of the tracks in the panel of the tracks: Draw the terrain to the track, of the selected tracks or of their whole run, Restore the terrain, each one step of the history, the terrain following the tracks edited or not, and Tracks onto the terrain and Terrain under the tracks for all the tracks of the scenery

The formation of a track as it is already was taken out of the terrain when the track was shaped again, as after a change of its properties alone: the formations the tracks still have are no longer counted as gone. Selftest trackterrain pull|restore <tracks>.

application/editormodeselftest.cpp

@@ -157,6 +157,7 @@ editor_mode::selftest_result editor_mode::selftest_dispatch(std::string const &c
 //                                        with the timings and counts of the renderer
 //   fittime <metres>...                  the grade line of a straight over rolling ground of each length fitted, as at a click, and the time the
 //                                        frame waits for it while the track is laid, the line fitted on the thread of the fitter
+//   trackterrain <pull|restore> <track>...   the terrain drawn to the tracks, or their formations taken out of it, as the panel of the tracks
 //   terrainhash                          a hash of the heights of the terrain chunks in memory, to compare the ground two builds made
 //   rebuildall                           the geometry of every path in the sections made already laid anew, the time it took logged,
 //                                        and the 3d sleepers of all the tracks laid anew, timed apart