Added father_alive field to Orphan model

Jira story: https://osraav.atlassian.net/browse/OSRA-221

First task: https://osraav.atlassian.net/browse/OSRA-222

- Added a new field "father_alive" to the Orphan model and to its views, specs and features.
- Added validation for the existence of the new boolean field only without any business logic validation.

OSRA-221 #code-review