Generate UUID URNs.
See RFC 4122 (https://tools.ietf.org/html/rfc4122).
Generate a version 4 (random) UUID as a RDF.IRI.
RDF.IRI
cast(String.t()) :: {:ok, RDF.IRI.t()} | {:error, any()}
cast!(String.t()) :: RDF.IRI.t()
generate() :: RDF.IRI.t()
to_string(RDF.IRI.t()) :: {:ok, String.t()} | {:error, atom()}