Support AWS EMF Version 0

[khanhntd]

Same as this PR #20314

Description:
Currently, awsemfexporter will group all the metrics, translate to fields and setting the fields with exported metrics as EMF version 1 -

"_aws": {
					"CloudWatchMetrics": [
					{
						"Namespace": "ECS",
						"Dimensions": [ ["ClusterName"] ],
						"Metrics": [{"Name": "memcached_commands_total"}]
					}
					],
					"Timestamp": 1668387032641
			  	}

Therefore, adding support for EMF version v0 and a flag for customers to make a difference between Version 0 and Version 1 (e.g EMF v0)

				{
					"Version": 0,
					"CloudWatchMetrics": [
					{
						"Namespace": "ECS",
						"Dimensions": [ ["ClusterName"] ],
						"Metrics": [{"Name": "memcached_commands_total"}]
					}
					],
					"Timestamp": 1668387032641
			  	}

This can be validated by send metrics with awsemfexporter

Link to tracking Issue:
N/A

Testing:
There are two tests I have done:

• By running go test with awsemfexporter, the result is

khanhntd@88665a0eaf54 awsemfexporter % go test ./...
ok      github.com/open-telemetry/opentelemetry-collector-contrib/exporter/awsemfexporter       2.409s

• By using the following configuration for awsemfexporter with prometheus, here is the following result:
  
  Documentation:
  https://docs.aws.amazon.com/AmazonCloudWatch/latest/monitoring/CloudWatch_Embedded_Metric_Format_Specification.html#CloudWatch_Embedded_Metric_Format_Specification_structure