Java API: Ability to input OSM data via primitive types instead of an XML string

[BudgieInWA]

In order to avoid serialising the OSM data into XML in Java just to deserialise it in Rust, we should provide the ability to get OSM data into StreetNetwork from a collection of floats and strings.

My idea is to create bare-bones Java types to represent the OSM nodes and ways and translate them into an osm_reader::Document in osm2streets-java.