feat(config): exporter plugin loading via entry points for declarative config#5128

MikeGoldsmith wants to merge 2 commits intoopen-telemetry:mainopen-telemetry/opentelemetry-python:mainfrom

MikeGoldsmith:mike/config-exporter-plugin-loadingMikeGoldsmith/opentelemetry-python:mike/config-exporter-plugin-loadingCopy head branch name to clipboard