Geocoder based on OpenStreetMap data

[Perdjesk]

Goals:

• Replaces current geocoder data source from GeoNames to OSM data.
• Feeds OSM data into Apache Lucene
• Serve existing API geocoding endpoints with OSM data and Lucene index

Non-goals:

• Extend with new features (such as inverse queries lat/long to entity)

Issues:

• [x] #779
• [ ] Serve basic text to location queries through API
• [ ] Better consistent handling of testing against OSM node type vs geometry type when mapping to Lucene document