OSRA-300 split `father_name`: cleanup

OSRA-307 clean up temporary methods

 - remove `Orphan#father_name=` & spec
 - retain `Orphan#father_name` (used in many views) & clean up spec
Merge pull request #238 from NikitaAvvakumov/osra-307-father-name-split-cleanup

OSRA-300 split `father_name`: cleanup