[FEATURE] CloudWatch Metrics Support with Federated PPL Query Engine

[rupal-bq]

Creating this placeholder issue to follow up on #561 for extending support to AWS CloudWatch. We can follow similar requirement and design as #561 while extending support to CloudWatch.

I will update issue with following content soon.
TODO-

• Add ppl queries on CloudWatch examples with details
• Differences from Prometheus where applicable
• Add task breakdown

[rupal-bq]

This video demonstrates the POC for some basic CloudWatch Metrics queries with PPL Query Engine.

Screen.Recording.2023-04-03.at.2.18.19.PM.mov

Please note that default values were used for some arguments like starttime, endtime, stats, period here. AWS SigV4 is used for authentication.

[anirudha]

Upload.from.GitHub.for.iOS.MOV

thanks @rupal-bq