Real talk: can we kill floats dag-cbor wide

[bumblefudge]

@expede Quick search of this gh org only shows floats in testing harness and test-cases and a footnote about IEEE timestamps being permitted to be JSNums, but no data model references to anything that SHOULD explicitly be typed as floats. Will anything break (for people using JWT/JS/JSON tooling and outsourcing CBOR translation to libraries) if DAG-CBOR bans floats? Can someone who knows the "I am not touching CBOR directly" downstream users tag them in this post to help us confirm no one's "JS Num" usage is actually float where it counts?