Add Micrometer Observation support to Spring Dapr Messaging

[artur-ciocanu]

Description

This PR adds support for Micrometer Observation into Spring Dapr Messaging. If everything goes well we will add similar support to Spring Dapr Data. This PR is heavily inspired and is a continuation of this PR: #1126.

In this PR I didn't enable any Project Reactor Hooks for context propagation. If we want to have context data being sent to OTEL or any other Micrometer exporter, this should be controlled by spring.reactor.context-propagation=auto Spring Boot application configuration. More details can be found here: https://docs.spring.io/spring-boot/reference/actuator/observability.html.

Issue reference

We strive to have all PR being opened based on an issue, where the problem or feature have been discussed prior to implementation.

Please reference the issue this PR will close: #1149

Checklist

Please make sure you've completed the relevant tasks for this PR, out of the following list:

• Code compiles correctly
• Created/updated tests
• Extended the documentation

[artur-ciocanu]

@artursouza @cicoyle and @salaboy when you have a chance could you please take a look. Thank you!

[artur-ciocanu]

@salaboy I would really appreciate if you could take this PR for "a ride" using this "spring.reactor.context-propagation=auto" Spring Boot configuration to see if traces land in Zipkin or any other tool that you played with in this PR: #1126.

Thanks in advance!

[salaboy]

@artur-ciocanu I will check it out.. So.. this PR is following what I did on my PR, but not adding this -> https://github.com/dapr/java-sdk/pull/1126/files#diff-f86931381933e4ae24b3f860afc7618f23aecb516cea8bfd0ce627b16bf64e19R100 which is enabled by the property: spring.reactor.context-propagation=auto , am I right? are there any other significant changes?

[artur-ciocanu]

@artur-ciocanu I will check it out.. So.. this PR is following what I did on my PR, but not adding this -> https://github.com/dapr/java-sdk/pull/1126/files#diff-f86931381933e4ae24b3f860afc7618f23aecb516cea8bfd0ce627b16bf64e19R100 which is enabled by the property: spring.reactor.context-propagation=auto , am I right? are there any other significant changes?

Exactly, since this is intended to be used in a Spring Boot environment, it is better to have this controlled via application configuration/properties and not enable it in the Dapr Messaging component.