feat(editor): heightmap terrain from the terrain model of GUGiK, fitted to the tracks of the scenery

- editorNmt: squares of 500 m of the NMT at 1 m from the WCS service of geoportal.gov.pl, as GeoTIFF, fetched in the
  background, kept in editor/cache/nmt and sampled in the coordinates of the scenery, placed as its orthophoto is
- the terrain panel's Terrain model section: Fit to the tracks moves the model up or down by the median of the
  differences to the formation of the tracks (Biała Podlaska, built at 0: -145.73 m, 0.28 m around it); Along the tracks
  and Around the camera make the chunks as the model comes in; each path gets its formation and slopes 1:1.5 as a modifier
  of the terrain, laid over each other into one corridor, bridges and tunnels keep the model; the orthophoto is turned
  on and laid onto the new ground
- the http client of the orthophoto in editorHttp, shared; fill_from_nearest in editormodeshared.h
- after the generator of Hirek (MaszynaTerrainGenerator): the WCS requests, the cache of squares, the corridor by envelopes
- self-tests nmtfit, nmtmake, nmtwait

CMakeLists.txt

@@ -200,6 +200,8 @@ set(SOURCES
 "editor/editorInfra.cpp"
 "editor/editorTerrainStreamer.cpp"
 "editor/editorOrthophoto.cpp"
+"editor/editorHttp.cpp"
+"editor/editorNmt.cpp"
 "editor/editorPreviews.cpp"
 "editor/editorIcons.cpp"
 "editor/editorClips.cpp"
@@ -213,6 +215,7 @@ set(SOURCES
 "application/editormoderecords.cpp"
 "application/editormodeswitchdrive.cpp"
 "application/editormodeswitchtool.cpp"
+"application/editormodenmt.cpp"
 "application/editormodeswitchslide.cpp"
 "application/editormodeswitchdesign.cpp"
 "application/editormodetrackbed.cpp"