Implement fallback logic in APM Server to derive `event.outcome` from `status_code` for http `transaction` and `span`. Logic should be aligned with what is defined in the [spec](https://github.com/elastic/apm/blob/master/specs/agents/tracing-transactions.md#transaction-outcome) and what is implemented for otel https://github.com/elastic/apm-server/pull/4127 Update the spec accordingly when implementing.
Implement fallback logic in APM Server to derive
event.outcomefromstatus_codefor httptransactionandspan.Logic should be aligned with what is defined in the spec and what is implemented for otel #4127
Update the spec accordingly when implementing.