Add OpenTelemetry support?

[jeromekelleher]

Prompted by an issue on Zarr (zarr-developers/zarr-python#2958) I wonder if we should implement OpenTelemetry support? We are going to end up with quite a complex and opaque execution stack by the time we've implemented readahead caching of variant chunks combined with complex query evaluation, so it could be a good thing to bake in from the start.

However, I know essentially nothing about OpenTelemetry, so it could be a complete mismatch.

[jeromekelleher]

The opentelemetry-api package that the source would depend on has no real dependencies, so it should be non-intrusive for applications that don't need it.