Add get geocode data method to interface

src/Interface/Entity/GeocodeInterface.php

@@ -17,6 +17,13 @@ interface GeocodeInterface
 
     public function setLongitude(float $lon): self;
 
+    /**
+     * Used by {@see Pcm\GeocodeBundle\Service\Geocoder} to retrieve raw data for geocoding.
+     *
+     * @return string Data to use when geocodind an entity
+     */
+    public function getGeocodeData(): string;
+
     /**
      * @return bool True if both latitude and longitude are set and are not (0, 0)
      */