Feature: Archive Retrieval

[rosemcc]

This pull request introduces the archive retrieval workflow to the project, adding support for restoring archived data from object storage back to a user-accessible location. It includes new models, API request/response schemas, and core logic for managing retrieval jobs.

Archive Retrieval Workflow Implementation:

• Added the ArchiveRetrieval SQLModel and RetrievalJobStage enum in models/retrieval.py to track retrieval jobs and their lifecycle stages, supporting resume and failure handling.
• Introduced CreateRetrievalRequest and CreateRetrievalResponse models for API requests and responses when initiating a retrieval job.
• Implemented S3 utility functions in activescale.py for restoring archived objects (initiate_object_restore), polling their availability (is_object_ready_for_download), and streaming downloads to disk (download_file_to_disk).

Configuration:

• Added new settings in config.py for controlling retrieval behavior, including the ActiveScale bucket name, restore duration, polling intervals, and maximum wait time.

BagIt Validation:

• Added a utility function validate_bag in manifests.py to verify the integrity of BagIt archives as part of the retrieval and extraction process.