feat(opentelemetry-instrumentation-aws-lambda): Handle event when coming from an API Gateway, see #999

[NPellet]

Which problem is this PR solving?

Enhancement proposal as discussed in #999

Short description of the changes

When we determine that the Lambda has been triggered from the API Gateway, we create a new span (wrapping the lambda span itself), giving it the name of the path

Given https://docs.aws.amazon.com/apigateway/latest/developerguide/set-up-lambda-proxy-integrations.html (See "Output format of a Lambda function for proxy integration") we analyze the statusCode replied by the lambda, and fail the span if that error is < 200 or >= 400.

Reacting to thrown exceptions doesn't fail the span, but the exception gets recorded.

I think creating a wrapping span makes more sense than annotating the existing one. It allows a clear separation in the tracing UI between lambdas that are called through SQS, the event bridge, etc. and the ones triggered through the Gateway.

[NPellet]

By the way, this is how it would look in Jaeger (juste tested on a Lambda):

[NPellet]

I guess this doesn't respect the specification: https://opentelemetry.io/docs/reference/specification/trace/semantic_conventions/http/#status

Because I set the status to errored when replying 400 or 500.
But to be honest I don't understand the motivation behind this part of the spec. If the caller is not instrumented then we can raise no alert due to a failed Gateway API request.

[NPellet]

Edited to add the query parameters, the path parameters and the headers as span attributes:

[NPellet]

Added configuration to select whether returning error codes should set the span status to failed or not:

Configuration:

 detectApiGateway?: {
    enable: true,
    errorCodes?: Array<RegExp | number>
  }

When using errorCodes: [ 400 ], only the error code 400 will set the span status to error, otherwise it will be set to ok

When using errorCodes: [/^4[0-9]{2}$/], codes 400-499 will set the span status to error, otherwise it will be set to ok

When using errorCodes: undefined, the span status will be left unset

Essentially, any match in the array will set the span status to error

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