Figure out better interface

[honzajavorek]

I don't like how the library currently works. It should transparently construct requests to the Fio API and return responses as nice PyDantic objects/dicts. I don't think it should do much more (retries, type conversions, etc. are fine). I don't like how it tries to separate info and transactions into separate methods, although the original API has no such thing, and I think such stuff should be deprecated. Maybe there could be minimal caching involved to provide info if called right after transactions, etc., but I'm afraid this only adds complexity for no added benefit.