[FEATURE] Use EMF metric logging for custom metrics instead of sending directly to CloudWatch

[asuresh8]

Is your feature request related to a problem?
Because the code is running alongside a fluentbit daemon, it would be more efficient to just write the logs to file and let fluentbit send them to CloudWatch periodically.

What solution would you like?
I want a different metrics emitter that writes metrics to EMF formatted log files. I want to configure some properties to be able to that metric emitter as well as configure where the log files will get dropped.

What alternatives have you considered?
None. I don't have putMetricData permissions in Spark to the existing CloudWatch reporter doesn't work

Do you have any additional context?
No