#3377 refactor: Move stream state manipulation into a state management class Pull request opened by edgarrmondragon ## Summary by Sourcery Extract stream state handling into a dedicated StreamStateManager class and update Stream to delegate all state-related operations to it. Enhancements: • Centralize stream state, partition, and replication key management logic in a new StreamStateManager helper class. • Move replication mode constants to the catalog module for reuse across the SDK. • Improve logging and behavior around starting replication values, progress markers, and sort errors during sync. • Adjust tap-countries HTTP caching configuration to ignore User-Agent differences and include headers in the cache key. Tests: • Add a comprehensive test suite for StreamStateManager covering initialization, partition handling, replication behavior, progress markers, resumability checks, and error logging. • Update parent/child stream snapshot fixtures to reflect the refactored state handling behavior. meltano/sdk