Send `sentry-org_id` in baggage

[mydea]

We want to make sure to send the org_id in baggage with outgoing requests, so that other SDKs can verify strict trace continuation.

1. The org id can be extracted from the DSN via regex, see https://develop.sentry.dev/sdk/telemetry/traces/#stricttracecontinuation
2. Optionally users should be able to pass orgId to their sentry init, which should take precedence if set (this is really more of a edge case/power user thing - on saas, DSN extraction should always work!)
3. If nothing can be found/extracted, no baggage entry should be set
4. This should be sent both in browser as well as in node.

[github-actions]

A PR closing this issue has just been released 🚀

This issue was referenced by PR #16305, which was included in the 9.20.0 release.