Extend OTLP receiver to publish via EMF logs

[sky333999]

Description of changes

#1361 introduced the support for an OTLP plugin for publishing metrics via PutMetricData to CloudWatch.
This PR extends the ability to use the OTLP plugin to publish metrics as EMF logs via PutLogEvents to CloudWatch.

• Introduces otlp section under logs -> metrics_collected that can either be a json blob or an array of json blobs for multiple listeners.
• OTLP Metrics are setup to flow through our a new hostDeltaMetrics/cloudwatchlogs pipeline using:
  • otlpreceiver - to receive the metrics on both HTTP and gRPC endpoints
  • cummulativetodelta processor - to convert cumulatives to deltas by default when publishing to CloudWatch
  • batch processor - to respect the force_flush_interval in the logs section of the agent config
  • awsemfexporter - to publish as EMF logs via PutLogEvents API calls to CloudWatch
• Serves as a passthrough plugin where all OTLP metrics sent are passed along as CloudWatch metrics without the need for explicit EMF metric declarations. Similarly, all resource and datapoint attributes are converted to dimensions on the metrics without any rollups i.e. they are sent along at the same granularity at which they are received.
• EMF logs are sent to aws/cwagent log group containing a log stream per unique run of the agent i.e. the log stream is based off a UUID generated on each run. Example log stream: otel-stream-52215dd6-abfa-44cb-a23d-25d79d1278fd.
• Metrics from EMF logs are extracted into the CWAgent namespace.
• Supports TLS configuration.

License

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Tests

• Updated unit tests
• Manually tested using a OTLP sample app

Sample config:

{
  "logs": {
    "metrics_collected": {
      "otlp": {
        "grpc_endpoint": "0.0.0.0:4317",
        "http_endpoint": "0.0.0.0:4318"
      }
    }
  }
}

Sample EMF log event:

{
    "CloudWatchMetrics": [
        {
            "Namespace": "CWAgent",
            "Dimensions": [
                [
                    "service.name",
                    "roll.value",
                    "telemetry.sdk.language",
                    "telemetry.sdk.name",
                    "telemetry.sdk.version",
                    "telemetry.auto.version"
                ]
            ],
            "Metrics": [
                {
                    "Name": "dice.rolls"
                }
            ]
        }
    ],
    "Timestamp": "1728235699078",
    "Version": "0",
    "roll.value": "2",
    "service.name": "unknown_service",
    "telemetry.auto.version": "0.46b0",
    "telemetry.sdk.language": "python",
    "telemetry.sdk.name": "opentelemetry",
    "telemetry.sdk.version": "1.25.0",
    "dice.rolls": 0
}

Requirements

Before commit the code, please do the following steps.

1. Run make fmt and make fmt-sh
2. Run make lint