Add support to emit metric to the target AMP workspace

[weicongw]

Add support to emit metric to the target Amazon Managed Service for Prometheus workspace
Beta

Issue #, if available:

Description of changes:

• Add support to emit metric to the target Amazon Managed Service for Prometheus workspace
• The test support emitting metric from cross account cross region
• If amp url is not set, the test will not emitting metics
• Emit NCCL test avg bus bandwith metric
• Add metadata label to the metric
• Add/update readme

Test

go test -timeout 60m -v . -args -nvidiaTestImage public.ecr.aws/o5d5x8n6/weicongw:nvidia --efaEnabled=true --feature=multi-node --ampMetricUrl=https://aps-workspaces.us-west-2.amazonaws.com/workspaces/ws-9f8fe538-f707-46e7-863c-26bfb192dc52/api/v1/remote_write --ampMetricRoleArn=arn:aws:iam::665181186642:role/amp
...
        [1,0]<stdout>:# Out of bounds values : 0 OK
        [1,0]<stdout>:# Avg bus bandwidth    : 3.68456 
        [1,0]<stdout>:#
        [1,0]<stdout>:
        
    mpi_test.go:145: Emitting nccl test metrics to AMP

Query the metric from AMP

export AMP_QUERY_ENDPOINT=https://aps-workspaces.us-west-2.amazonaws.com/workspaces/ws-9f8fe538-f707-46e7-863c-26bfb192dc52/api/v1/query

awscurl -X POST --region us-west-2 \
--service aps "${AMP_QUERY_ENDPOINT}" \
-d 'query=nccl_average_bandwidth_gbps[60m]' \
--header 'Content-Type: application/x-www-form-urlencoded'

{"status":"success","data":{"resultType":"matrix","result":[{"metric":
{"__name__":"nccl_average_bandwidth_gbps","ami_id":"ami-0cd7612ff47454cd6",
"aws_ofi_nccl_version":"1.9.1","efa_count":"1","efa_enabled":"true",
"efa_installer_version":"1.34.0","instance_type":"p4de.24xlarge",
"kubernetes_version":"1.30+","nccl_version":"2.18.5","node_count":"2",
"nvidia_driver_version":"550.90.07","os_type":"Amazon Linux 2"},
"values":[[1726791286.534,"3.62432"],[1726794564.87,"3.68456"]]}]}}

By submitting this pull request, I confirm that my contribution is made under the terms of the Apache 2.0 license.