Allow S3Paths to be stored in Arrow files

[haberdashPI]

It would be convenient if S3Paths would seamlessly serialize to Arrow files (via Arrow.jl).

As described by @ericphanson:

We’d want to PR AWSS3 to add a dependency on ArrowTypes.jl (which is very light) and then setup custom serialization (https://arrow.juliadata.org/dev/manual/#Custom-types) to serialize out an S3Path as a string, and to load it back from a string as an S3Path

[haberdashPI]

(FYI: happy to try to attempt a PR for this; might be able to get a draft started later today)

[omus]

I think #175 is a prerequisite of this. We definitely don't want to be serializing the config information for Arrow

[ericphanson]

My thought is we can just ignore the config and serialize it out as a string like "s3://bucket/key" (with a type tag calling it an S3Path), and then to deserialize, just parse it back (with the global config at parse time). So it wouldn't need #175

[omus]

The reason I think we should require #175 is that I think we should only perform Arrow serialization on S3Paths that don't include a explicit configuration.