Contact paragraph use location field from localgov_geo

[finnlewis]

The location field in the localgov_paragraphs module has an address and location, but it is a different format from the address field on localgov_geo and also uses a different geolocation system.

Working on the Lambeth project it seems wise to be consistent here, using a single pattern for adding an address and optional geolocation.

This ticket is to track that and discuss implications.

[msayoung]

@finnlewis is this a duplicate of #10