[Feature]: Add Role Assumption Logic for S3 operations

[shivanand007]

Currently, the codebase only supports basic AWS credentials through environment variables. We should add support for AWS IAM Role assumption to enhance security and follow AWS best practices.

Current Behavior

• Only supports basic AWS credentials (AWS_ACCESS_KEY_ID and AWS_SECRET_ACCESS_KEY)
• No support for assuming IAM roles

Proposed Changes

1. Add support for role assumption configuration through:

   • Environment variables (AWS_ROLE_ARN, AWS_ROLE_SESSION_NAME)
   • Constructor parameters in S3Resource class

2. Implement STS client integration for assuming roles

3. Update documentation to include role assumption setup

Technical Details

• Use AWS STS (Security Token Service) to obtain temporary credentials
• Update S3Client configuration to use temporary credentials when role ARN is provided
• Handle credential refresh when temporary credentials expire

Benefits

• • Support for cross-account access
• • Enhanced security through temporary credentials
• • Better alignment with AWS security best practices