Messaging: publish operation type is pub/sub/topic specific

[lmolkova]

Extracted from #1205

messaging.operation.type = publish is specific to pub/sub/topic.

send would sound more neutral and apply to pub/sub and MQ. E.g. GCP pub/sub, Azure EventHubs and Kafka use send.

We should consider changing operation type and also metric name to use send.

[mamwl1]

The JMS spec, https://jakarta.ee/specifications/messaging/3.0/jakarta-messaging-spec-3.0.pdf, also uses send.
For example see: https://jakarta.ee/specifications/platform/8/apidocs/javax/jms/jmsproducer which has a set of send and receive methods which apply to both queues and topics.

[pyohannes]

E.g. GCP pub/sub, Azure EventHubs and Kafka use send.

Ironically, RabbitMQ prefers the term "publish" 😄 .

I'm not generally opposed to using the term "send", however, I think we should be consistent.

Currently we give this definition in semantic conventions, establishing the term for messaging semantic conventions:

"Publishing" is the process of sending a message or batch of messages to the intermediary or consumer.

Do you think we should then generally revise our use of the term "publish" in messaging semantic conventions, and go with "send" instead?

[mamwl1]

Yes, I was going to propose adjusting the docs to use send generally instead of publish.