Add open tracing to pulsar go clinet

[maraiskruger1980]

As suggested by @sijie

Here is the PR to add open tracing to the pulsar go client directly.
This is replicating what the java tracer does:
https://github.com/streamnative/pulsar-tracing
The usage is stipulated in the readme.md file

[wolfstudy]

@maraiskruger1980 Great Job., thanks for your contribution. Can you add some test cases for this?

It seems that we can also add similar functions to the reader. Are you also interested in this?

[wolfstudy]

It seems that we can also add similar functions to the reader. Are you also interested in this?

For this, you can also send a new pull request to impl it.

[maraiskruger1980]

@maraiskruger1980 Great Job., thanks for your contribution. Can you add some test cases for this?

It seems that we can also add similar functions to the reader. Are you also interested in this?

@wolfstudy I added tests and made some improvements

[wolfstudy]

LGTM +1

[wolfstudy]

Here is the PR to add open tracing to the pulsar go client directly.
This is replicating what the java tracer does:
https://github.com/streamnative/pulsar-tracing
The usage is stipulated in the readme.md file

[Anonymitaet]

@maraiskruger1980 thanks for your contribution! Want users to know this great feature and know how to use it?

If so, could you please add docs to Pulsar - Go client?
(How about adding a section "Monitoring" and add the docs under that section? Explanations of "What is the feature" & "How to use the feature" are needed. You can take How to trace Pulsar messages with OpenTracing and Jaeger and OpenTracing Pulsar Client as references.

Then I would like to help review. Feel free to ping me if needed, thanks.