Restore Integration test JSON schema serialization

[alamb]

Is your feature request related to a problem or challenge? Please describe what you are trying to do.
@maxburke noted:

it looks like from arrow 20 to 22 it was made conditional on the json feature, but it's now... gone?

@tustvold says

It was removed as it isn't meant as a stable serialization format

There is still serde::Serialize implemented for Schema if the corresponding feature is enabled but this isn't backwards compatible with the old serialization format

Describe the solution you'd like
I think publishing an arrow-integration-test crate containing the decoding logic for this format makes sense

Describe alternatives you've considered
Copy the code from git into new repos

Additional context
https://the-asf.slack.com/archives/C01QUFS30TD/p1665180205354589

[alamb]

Published on crates.io as https://crates.io/crates/arrow-integration-test/25.0.0 (though it has no readme for some reason 🤔 ) cc @maxburke