AWS S3 Exporter

[mheffner]

We should support exporting to AWS S3 to allow for storing telemetry in cheap cloud object storage.

Formats we should support:

• JSON
• Parquet

Compression:

• Gzip
• Zstd

The AWS SDK provides a fairly robust S3 client, so it would behoove us to reuse this instead of building our own client based on Hyper. However, we'll need to figure out how to incorporate this into our exporter model without duplicating a lot of the existing framework for http-based exporters. Ideally we'll want to finish merging the OTLP and HTTP exporter code bases first.

The AWS SDK is also quite large, so we'll have to measure how much this adds to the code base and compiled binary size.