fix: implement pruning and validation for COL_BLOB_STATUS

[EFCCWEB3]

Description

This PR addresses Issue #29 regarding the unbounded growth of the COL_BLOB_STATUS column family.

Changes

• Storage Layer: Added a prune() method to the BlobStatusDB trait and implemented it in Storage.
• Pruning Logic: Updated storage/src/slice_db.rs to ensure that when an epoch is pruned, all corresponding statuses in COL_BLOB_STATUS are also deleted.
• DA Handler: Added epoch validation in check_data_upload and check_data_verified to prevent the node from processing and storing logs from epochs outside the retention window.
• gRPC Service: Added a check in check_blob_status to reject incoming sign requests for expired epochs.

Closes #29