Refactor OneLake integration to streamline secret management and token handling

- Removed ONELAKE_BLOB_TOKEN and related references from README and codebase.
- Updated OneLakeTokenAudience enum to exclude OneLakeBlob.
- Simplified OneLakeCredentials structure by removing blob variable.
- Enhanced secret creation logic to automatically create necessary Azure and OneLake secrets from environment variables.
- Improved error handling for missing tokens during secret creation.
- Updated HTTP utility functions to utilize URL encoding for client credentials.
- Refactored storage extension to attempt auto-creation of secrets on attach.
- Cleaned up commented-out debug print statements across various files.
- Updated vcpkg.json to include azure-core-cpp with curl feature.