feat(tokenization): implement atomic batch operations

[allisson]

• Added support for atomic batch processing in the Tokenization Engine.
• Implemented CreateBatch and GetBatchByTokens in both PostgreSQL and MySQL repositories with optimized batch retrieval.
• Added TokenizeBatch and DetokenizeBatch to the usecase layer, ensuring atomicity via TxManager.
• Exposed new REST API endpoints:
  • POST /v1/tokenization/keys/:name/tokenize-batch
  • POST /v1/tokenization/detokenize-batch
• Defined batch request/response DTOs with validation (enforcing a 100-item limit).
• Updated the metrics decorator to track latency and operations for batch tasks.
• Injected TxManager into the tokenization usecase through the DI container.
• Added comprehensive unit tests for DTOs, usecases, and handlers.
• Expanded integration flow tests to verify success and atomicity across both database engines.
• Updated OpenAPI specification and Engine documentation with batch usage examples.