message: Use direction offset constants in MapViewStateHelper
diff: #include "../Constants.h"
  #include "../StructureCatalogue.h"
  +#include "../DirectionOffset.h"
  #include "../Things/Structures/RobotCommand.h"
  @@ -152,10 +153,11 @@ bool checkStructurePlacement(Tile* tile, Direction dir)
  */
  bool validTubeConnection(TileMap* tilemap, int x, int y, ConnectorDir dir)
  {
  - return checkTubeConnection(tilemap->getTile(x + 1, y, tilemap->currentDepth()), DIR_EAST, dir) ||
  - checkTubeConnection(tilemap->getTile(x - 1, y, tilemap->currentDepth()), DIR_WEST, dir) ||
  - checkTubeConnection(tilemap->getTile(x, y + 1, tilemap->currentDepth()), DIR_SOUTH, dir) ||
  - checkTubeConnection(tilemap->getTile(x, y - 1, tilemap->currentDepth()), DIR_NORTH, dir);
  + const auto point = NAS2D::Point<int>{x, y};
  + return checkTubeConnection(tilemap->getTile(point + DirectionEast, tilemap->currentDepth()), DIR_EAST, dir) ||
  + checkTubeConnection(tilemap->getTile(point + DirectionWest, tilemap->currentDepth()), DIR_WEST, dir) ||
  + checkTubeConnection(tilemap->getTile(point + DirectionSouth, tilemap->currentDepth()), DIR_SOUTH, dir) ||
  + checkTubeConnection(tilemap->getTile(point + DirectionNorth, tilemap->currentDepth()), DIR_NORTH, dir);
  }
  @@ -166,10 +168,11 @@ bool validTubeConnection(TileMap* tilemap, int x, int y, ConnectorDir dir)
  */
  bool validStructurePlacement(TileMap* tilemap, int x, int y)
  {
  - return checkStructurePlacement(tilemap->getTile(x, y - 1, tilemap->currentDepth()), DIR_NORTH) ||
  - checkStructurePlacement(tilemap->getTile(x + 1, y, tilemap->currentDepth()), DIR_EAST) ||
  - checkStructurePlacement(tilemap->getTile(x, y + 1, tilemap->currentDepth()), DIR_SOUTH) ||
  - checkStructurePlacement(tilemap->getTile(x - 1, y, tilemap->currentDepth()), DIR_WEST);
  + const auto point = NAS2D::Point<int>{x, y};
  + return checkStructurePlacement(tilemap->getTile(point + DirectionNorth, tilemap->currentDepth()), DIR_NORTH) ||
  + checkStructurePlacement(tilemap->getTile(point + DirectionEast, tilemap->currentDepth()), DIR_EAST) ||
  + checkStructurePlacement(tilemap->getTile(point + DirectionSouth, tilemap->currentDepth()), DIR_SOUTH) ||
  + checkStructurePlacement(tilemap->getTile(point + DirectionWest, tilemap->currentDepth()), DIR_WEST);
  }
  