Enhance Synthetic Span Service Representation

[zarirhamza]

What does this PR do?

Rollout of span naming changes to align serverless product with tracer to create streamlined Service Representation for Serverless

Key Changes:

• Change service name to match instance name for all managed services (aws.lambda -> lambda name, etc) (breaking)
• Add span.kind:server on synthetic spans made via span-inferrer

Motivation

Improve Service Map for Serverless. This allows for synthetic spans to have their own service on the map which connects with the inferred spans from the tracer side.

Testing Guidelines

Unit and Integration tests updated accordingly.

Note that any span w/span.kind tags are automatically measured
Matching the service name to the instance name essentially removes the need for a base_service tag in some instances due to essentially removing service overrides

Additional Notes

These changes should be synchronized with tracer changes (TBD)

Types of Changes

• Bug fix
• New feature
• Breaking change
• Misc (docs, refactoring, dependency upgrade, etc.)

Check all that apply

• This PR's description is comprehensive
• This PR contains breaking changes that are documented in the description
• This PR introduces new APIs or parameters that are documented and unlikely to change in the foreseeable future
• This PR impacts documentation, and it has been updated (or a ticket has been logged)
• This PR's changes are covered by the automated tests
• This PR collects user input/sensitive content into Datadog
• This PR passes the integration tests (ask a Datadog member to run the tests)

[purple4reina]

Good news. I'm fairly certain this change will not impact billing. Check out this method in dd-go https://github.com/DataDog/dd-go/blob/ba9638063271fa8bec5ce732d88ed0244795cca9/trace/apps/trace-spans-meta-extractor/usage_points.go. We look for a spans with name "aws.lambda" (not service or operation name) and create a billing metric point for each. I was worried this change in the service would impact that, but it looks like it won't.

Just to be sure, if you haven't already, check to make sure the datadog.serverless.traced_invocations metric is still created for each invocation.

[zarirhamza]

Is span.name and operation.name not the same thing? As long as operation.name is unchanged, it should be fine as long as I'm understanding the code, the same way you are.

[purple4reina]

Yeah, that's my understanding as well. Still worth double checking by testing these changes in the wild though.

[zarirhamza]

Going to wait for dd-trace-js version update to merge this changes with it and update the tracer dependency