Add address input and refactor federation stuff

Signed-off-by: Thomas Citharel <tcit@tcit.fr>

config/dev.exs

@@ -50,6 +50,8 @@ config :mobilizon, MobilizonWeb.Endpoint,
 # Do not include metadata nor timestamps in development logs
 config :logger, :console, format: "[$level] $message\n", level: :debug
 
+config :mobilizon, Mobilizon.Service.Geospatial, service: Mobilizon.Service.Geospatial.Nominatim
+
 # Set a higher stacktrace during development. Avoid configuring such
 # in production as building large stacktraces may be expensive.
 config :phoenix, :stacktrace_depth, 20