Return way names in all available languages

[yuryleb]

There are many countries with several official/unofficial languages and many streets/POI with names assigned for more than one language (name:<lang>). Is it possible to return all them not only the default name by public OSRM interface?

I suppose the StringView type in name-returning methods could be extended for this with a map of string_refs indexed by language code in addition to string_ref field for default name.

This allows OSRM frontends (OSRM Text Instructions as first example) to choose the names with language matched the current user's one and dynamically switch from one language to another also for route ways not for their instructions only.

Also this helps to provide some advanced language-dependent functionality to route directions, say grammatical cases applying to way names.