Added general procedure of hist containing subdirs of Result/Config.
With one special case, which is "TObjArray" name of dir. In this case, it will not be stored as TDir, but rather all contained elements will be stored separately in upper level hist_ directory. Tests are done to be sure, that recent bugs with hanoutput files (ATLASDQ-1076, ATLASDQ-1094) do not appear again.
Closes ATLASDQ-1117