[SPEC] OpenTelemetry Propagators

[AbhiPrasad]

https://github.com/open-telemetry/opentelemetry-specification/blob/main/specification/context/api-propagators.md

Use OTEL's propagators API to extract and inject sentry-trace and baggage headers.

[AbhiPrasad]

See example implementation: getsentry/sentry-javascript#6095