Django admin: Irrelevant data is not being cleared for domain information

[vickyszuchin]

Issue description

When changing org_type, on save, reset any existing and no longer relevant data (example: when changing org_type from federal to something else, clean up federal agency if it exists).

Acceptance criteria

• [ ] Identify all scenarios where we could be leaving dangling data on org_type changes
• [ ] Clean up the dangling data on save where applicable

Additional context

note by "on save" this refers to the save and continue button at the bottom of each request page:

slack thread

Links to other issues

• Related to: #1675 (when creating a request)

[vickyszuchin]

Updated information. Added slack thread and related ticket.

[vickyszuchin]

Accepted into the backlog. It is not urgent but Product suggests working this ticket with #1675 as a pair in the upcoming sprints (beyond sprint 43).

[vickyszuchin]

This ticket has been story pointed and meets DoR criteria. Moving it to "Ready".

[abroddrick]

I think reading this we should merge this one with #1675 and not keep both tickets. the other ticket is just missing the callout to check for any dangling data and that irrelevant data should be cleared on save.