Improve AWS Lamda support

[kenmuse]

To make it easier for users to deploy the sample on AWS Lambda, we need the following features:

• [x] Separate code for the Lambda handler
• [x] Automate Lambda build using SAM
• [x] Implement Feature for Dev Container with required tools
• [x] Integrate Secrets Manager
• [ ] Release image: Container image (requires workflow)
• [ ] Release file: Cloud formation template for container
• [ ] Release file: ZIP package (requires workflow)
• [ ] Release file: Cloud formation template for package
• [ ] Add documentation for deploying to /docs folder

Stretch goals:

• [x] Add integration tests