Registrant location labels and docs still say "org" after the home-address fallback #2845

Follow-up from #2844, which made registrant locations fall back to the person's own address when no work address is known. Two places still describe the old org-only behavior.

• AttendeesActiveFilters chip reads "Org country: …" — RegistrationLocations#registrant_ids_by_country falls back to the person's home address, so the chip can label a home-country match as an org one. The pre-existing "Org city: …" chip has the same problem now that registrant_ids_by_city_label carries home-address labels. Slightly at odds with the "not just work" naming the PR settled on.
• RegistrantCityBreakdown's header comment still says the Unknown bucket is "a linked org with no address on file". It's now a linked org with no address and no own address to fall back on.

Deliberately left out of #2844 to keep that diff to behavior.