Move SDK configuration into own package #1245
Description
Before opening a feature request against this repo, consider whether the feature should/could be implemented in the other OpenTelemetry client libraries. If so, please open an issue in opentelemetry-specification first.
Is your feature request related to a problem?
Per otel spec, most components should only depend on the API, and not the SDK. Because all of our configuration-management code is in the SDK, it's not usable by contrib modules etc which need to deal with config. So, we end up with duplicate code and inconsistent handling of config.
Describe the solution you'd like
If we break config related code (OpenTelemetry\SDK\Common\Configuration\*) into its own small package that other packages can use, then they can use config without requiring the SDK.
Describe alternatives you've considered
I once thought about creating a configuration-resolver interface, and writing a minimal config resolver in the API (matching the interface of the SDK version). The implementation was very similar to the SDK one. But, now that we also have config management in the Context package, that would create a circular dependency between API and Context.