Fix handling of non-subclassed Person.for_location

Person.criteria_for_types_for_location was breaking on nil _type
value. Since plain Person objects (i.e. Twitter ingested) don't have
reliable location data, return scope that has no effect.

Supports #237
Handle all errors w/ fallback address lookup

There are several possible GoogleCivicInfo errors for unrecognized
addresses. The fallback will simply return empty result if address is
malformed. Simple "typo, try again" can then be added to UI.

Supports #237
Refactor method

Supports #237
Report that address might be malformed in UI

If empty results are returned, ask if the address is correct.

Supports #237