Check and update doc for kafka notifications

[mapedraza]

fiware-orion/doc/manuals/orion-api.md

Lines 5053 to 5054 in af68461

	| `lastFailureReason`| Only on retrieval | string | Not editable, only present in GET operations. Describes the cause of the last failure (i.e. the failure occurred at `lastFailure` time). Not included in MQTT subscriptions.|
	| `lastSuccessCode` | Only on retrieval | number | Not editable, only present in GET operations. the HTTP code (200, 400, 404, 500, etc.) returned by receiving endpoint last time a successful notification was sent (i.e. the success occurred at `lastSuccess` time). Not included in MQTT subscriptions.|

[fgalan]

Not fully sure but getting these fields for KAFKA subscription would be hard (as far as I remember, in MQTT was not possible and KAFKA implementation is very close to MQTT one).

PR #4729 fixes the documentation to state this clear.

However, @orianar please have a look. If you find a setting these fields in KAFKA notification, let's do it (and maybe the same solution could be propagated to the MQTT case). In that case, PR #4729 should be overpassed by your PR fixing this. But if you don't find a good solution for this, let's merge PR #4729 and close this issue.

[orianar]

MQTT and Kafka do not provide success or failure codes because their protocols are asynchronous: the producer only publishes messages and never receives any response from the consumer, and the broker simply stores the messages without checking how they are processed. For Orion to support something similar, a special return channel would need to be created so that services could report their processing status back, and Orion would have to read and store that information. However, this is not necessary and does not align with how MQTT and Kafka are designed, since processing tracking is meant to be handled outside the broker, either by the consumers themselves or through external monitoring tools.

[fgalan]

@orianar by your commenta above and the LGTM at PR #4729 I understand we go for the

let's merge PR #4729 and close this issue.

solution :)

Thus, this issue is going to be closed.