pierre rognant issues

Results 3 issues of


                                            pierre rognant

Verify `splunk_hec_metrics` sink

- [x] Verify internal event processing metrics are tested via `assert_X_compliance` test helpers - [ ] Update `component_discarded_events_total` to match the new [instrumentation spec](https://github.com/vectordotdev/vector/blob/master/docs/specs/instrumentation.md#eventsdropped) by adding `reason` to the emitted...

sink: splunk_hec

domain: observability

Verify `splunk_hec_logs` sink

sink: splunk_hec

domain: observability

Verify `socket` sink

- [x] Verify internal event processing metrics are tested via `assert_X_compliance` test helpers - [x] Update `component_discarded_events_total` to match the new [instrumentation spec](https://github.com/vectordotdev/vector/blob/master/docs/specs/instrumentation.md#eventsdropped) by adding `reason` to the emitted logs,...

sink: socket