Django admin: Federal agency page updates

[zandercymatics]

Issue description

The federal agency page in django admin needs a few QOL and consistency updates to better reflect our established patterns. More specifically, we should change the "agency" and "federal type" fields.

Acceptance criteria

• Update "agency" field to read as "Federal agency" on the Federal Agency page to match other instances of that field.
  • Ensure that this change is also present on the table view.
• Update the "agency" field to be required
• Update the "federal_type" field to be required
• Remove helper text underneath the "Federal agency" field.

Additional context

Regarding AC #1: Note that the name on the frontend doesn't always need to match what is on the backend. If it makes more sense, one approach may be to use verbose_name rather than renaming the field in the DB. However you can change this if it is deemed necessary - but be aware of the refactor that it will entail.

Links to other issues

No response

[h-m-f-t]

@zandercymatics would this affect the data in current-full/federal? If so, how? (Added refinement label)