Integrate with Skywalking

[seeflood]

What would you like to be added:
Layotto already supports tracing,and next we hope to integrate with observability-related platforms such as Skywalking.

Details:
According to @wenxuwan, currently Layotto's tracing is based on MOSN's package,and MOSN already have done some integration work with Skywalking , so maybe we can reuse these code:

I haven't read these code and don't know how to reuse,so you can read through the existing code before working on this issue.

What we need:

• integrates Layotto with Skywalking
• A demo and document to show users how to use this feature. You can take MOSN's demo as an example

If you encounter problems, we can have a discussion in webchat group or online meeting.

Why is this needed:
See discussion in #309

[seeflood]

This issue will be assigned to @ZLBer

[github-actions]

This issue has been automatically marked as stale because it has not had recent activity in the last 30 days. It will be closed in the next 7 days unless it is tagged (pinned, good first issue or help wanted) or other activity occurs. Thank you for your contributions.

[github-actions]

This issue has been automatically closed because it has not had activity in the last 37 days. If this issue is still valid, please ping a maintainer and ask them to label it as pinned, good first issue or help wanted. Thank you for your contributions.

[seeflood]

@ZLBer Hi,are u still working on it? Or should I assign it to others?

[github-actions]

This issue has been automatically marked as stale because it has not had recent activity in the last 30 days. It will be closed in the next 7 days unless it is tagged (pinned, good first issue or help wanted) or other activity occurs. Thank you for your contributions.

[github-actions]

This issue has been automatically closed because it has not had activity in the last 37 days. If this issue is still valid, please ping a maintainer and ask them to label it as pinned, good first issue or help wanted. Thank you for your contributions.

[seeflood]

@stulzq is working on it

[github-actions]

This issue has been automatically marked as stale because it has not had recent activity in the last 30 days. It will be closed in the next 7 days unless it is tagged (pinned, good first issue or help wanted) or other activity occurs. Thank you for your contributions.