Codechange: Pass additional data as byte stream to command callbacks.

src/signs_cmd.cpp

@@ -116,7 +116,7 @@ CommandCost CmdRenameSign(DoCommandFlag flags, TileIndex tile, uint32 p1, uint32
  * @param p2 unused
  * @param text unused
  */
-void CcPlaceSign(const CommandCost &result, Commands cmd, TileIndex tile, uint32 p1, uint32 p2, const std::string &text)
+void CcPlaceSign(Commands cmd, const CommandCost &result, TileIndex tile, const CommandDataBuffer &)
 {
 	if (result.Failed()) return;