support for OTLP resource detectors

[zeitlinger]

Please describe the feature request.

Resource providers play an important role in troubleshooting, e.g. to identify which cloud availability zone has issues.

A list of providers can be found here:

• https://github.com/open-telemetry/opentelemetry-java-instrumentation/tree/main/instrumentation/resources/library
• https://github.com/open-telemetry/opentelemetry-java-contrib/blob/main/aws-resources/README.md
• https://github.com/open-telemetry/opentelemetry-java-contrib/blob/main/resource-providers/README.md

Additional context

• requires an (optional) dependency on https://central.sonatype.com/artifact/io.opentelemetry/opentelemetry-sdk-extension-autoconfigure-spi, which is stable
• implementation is pretty much copying a part of SDK auto-config
• the required ConfigProperties object can be populated from env vars, using this conversion