Code Review

This pull request implements dynamic CRC32C validation for appendable object uploads by updating the connection and writer logic to initialize hash functions from RPC response metadata. It also adds a stateful constructor to the CRC32C hash function. Feedback highlights a critical regression where a large suite of existing integration tests was deleted and replaced with experimental code. Additional suggestions include adding defensive checks for CRC32C field presence, utilizing existing library thread management instead of a custom thread pool in tests, and using environment variables instead of hardcoded strings for test configuration.