Thread-safe, multiple compression level support, proof of concept

[jmacd]

Just a note concerning how this library could be extended to support thread-safe configuration of compression settings.

For our project we needed this specifically for Zstd, and I used the following approach.

open-telemetry/otel-arrow#81

This allows us to configure up to 10 distinct encoder settings in a thread-safe way. I opened this issue to share the idea for consideration.

[mostynb]

Thanks for the pointer- I will take a look :)