Draft: feat: implement base client and AWS token verification
Relates to issue #567725 (closed)
This MR was created by Duo in Session 1112234
Changes
- Implement foundational BaseClient class with common HTTP operations and security controls
- Create AWS token verification client using STS GetCallerIdentity API
- Add response size validation (10KB limit) and timeout handling (5 seconds)
- Implement standardized error handling with NetworkError and ResponseError exceptions
- Add TokenStatus struct for consistent response format
- Support AWS SigV4 request signing for authentication
- Handle both AKIA* and ASIA* access key formats
- Extract AWS account, user ID, and ARN from API responses
- Implement comprehensive security measures (no sensitive data logging, proper error handling)
- Add metrics tracking for all requests (success, failure, duration)