Enhance DSpaceClient with DSpace Item API Functions

[mdwRepository]

The DSpaceClient class can be extended to include several new methods to interact with the DSpace Item API as documented in https://github.com/DSpace/RestContract/blob/main/items.md. These methods provide functionality for managing item relationships, access status, metrics, owning collections, and mapped collections.

Functions:

1. get_item_metrics

• Fetches metrics for a specified item.
• Handles network errors and API response status codes.

2. get_item_thumbnail

• Retrieves the thumbnail of an item, if available.
• Handles the following status codes:
  - 200 OK: Returns the thumbnail.
  - 204 No Content: Indicates no thumbnail is available.
  - 401 Unauthorized: Logs insufficient authentication.
  - 403 Forbidden: Logs insufficient permissions.
  - 404 Not Found: Logs that the item or thumbnail is missing.

3. get_item_owning_collection

• Retrieves the owning collection for a specified item.
• Handles errors when the item or owning collection cannot be retrieved.

4. update_item_owning_collection

• Updates the owning collection of a specified item.
• Handles the following status codes:
  - 204 No Content: Indicates success.
  - 403 Forbidden: Logs insufficient permissions or CSRF token issues.
  - Other: Logs any unexpected response.

5. get_item_mapped_collections

• Retrieves all mapped collections for a specified item.
• Handles error codes like 401, 403, 405, and 422.

6. add_item_mapped_collection

• Adds a new mapping between an item and a collection.
• Handles appropriate API response codes and errors.

7. delete_item_mapped_collection

• Removes a mapping between an item and a collection.
• Handles response codes for authentication, permissions, and entity processing.

8. get_item_relationships

• Retrieves relationships of an item.
• Handles response parsing and error logging.

9. get_item_access_status

• Fetches the access status of an item.
• Manages API responses for invalid parameters, missing items, and more.

Benefits:

• Provides a comprehensive interface for interacting with DSpace items.
• Improves error handling and robustness in API interactions.
• Aligns the client with the latest DSpace REST API specifications.