Sponsor affiliate validations

OSRA-209 https://osraav.atlassian.net/browse/OSRA-209
SponsorType must match affiliate type

- validate that sponsor_type matches affiliate on sponsor creation
- make sponsor_type, branch & organization readonly in sponsor
- disable selectors for Sponsor Type, Branch & Organization on the Sponsor Edit page

- update seeds, specs & features to conform to the new validation
:+1: