Use XML API for GCS

[tustvold]

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

GoogleCloudStorage currently uses a mix of the XML and JSON APIs. This is unfortunate and causes issues due to some functionality not being properly supported in the JSON APIs.

One challenge is fake-gcs-server lacks proper support for the XML APIs - fsouza/fake-gcs-server#331

Describe the solution you'd like

Switch to using the XML API for GCS

Describe alternatives you've considered

Additional context

[tustvold]

label_issue.py automatically added labels {'object-store'} from #4207

[onpaws]

Just wanted to say as a recent adopter of arrow-rs + GCS buckets, this PR will make an immediate difference for my project. Thank you :)