Correct parent organization selection for new principal organizations

[gjvoosten]

Admins can now also correctly find and select parent organizations when creating new principal organizations.

Release notes

Fixes #3004

User changes

• none

Super User changes

• none

Admin changes

• When creating a new principal organization, a parent organization can be found and selected. (For advisor organizations this was already the case.)

System admin changes

• none
• anet.yml needs change
• db needs migration
• documentation has changed
• graphql schema has changed

Checklist

• Described the user behavior in PR body
• Referenced/updated all related issues
• commits follow a repo#issue: Title title format and these 7 rules
• commits have a clean history, otherwise PR may be squash-merged
• Added and/or updated unit tests
• Added and/or updated e2e tests
• Added and/or updated data migrations
• Updated documentation
• Resolved all build errors and warnings
• Opened debt issues for anything not resolved here