Moved Service attributes to registry

[gregkalapos]

Changes

This PR is to moves service and service_experimental attributes to the attributes registry and make service resources reference the registry.

Merge requirement checklist

• CONTRIBUTING.md guidelines followed.
• Change log entry added, according to the guidelines in When to add a changelog entry.
  • If your PR does not need a change log, start the PR title with [chore]
• schema-next.yaml updated with changes to existing conventions.

[joaopgrassi]

@gregkalapos can you please fix the yamllint issues? then we should be good to merge :)

[github-actions]

This PR was marked stale due to lack of activity. It will be closed in 7 days.

[trisch-me]

@gregkalapos could you please update this PR?

[gregkalapos]

This is still pending on #820. I think #820 should be merged first and then I could update this.

Alternatively I could use the changes from #820, update this PR and maybe we could merge - I personally don't think that'd be ok, but happy to do so if others think it makes sense.

My understanding is that @lmolkova also wanted to merge #820 first and then update this PR, see: #807

Let me know how to proceed - otherwise I'll just wait for #820.

[gregkalapos]

#820 merged, I updated this PR.

[gregkalapos]

Currently fighting with areas-dropdown-check.

`Dropdowns in issue templates is out of date, please run "make generate-gh-issue-templates" and commit the changes in this PR.
Error: Process completed with exit code 1.

make generate-gh-issue-templates fails for me locally - trying to figure this out... 😢

Update: managed to run it, and pushed it. Issue was around sed on my mac - installed gsed, that worked.

[trisch-me]

@gregkalapos I had the same issue, have created a hint for it
https://github.com/open-telemetry/semantic-conventions/pull/876/files
@joaopgrassi FYI