Change Details

Implemented methods for managing the `blob-service-reverse-index` table. They will be needed in subsequent diffs. This is mostly the same approach as in D5693 (parent diff). [Link to the C++ counterpart](https://github.com/CommE2E/comm/blob/32d6628a1db51c4f1432fa471bf6508cd331f7d7/services/blob/src/DatabaseManager.cpp) Depends on D5693

Implemented methods for managing the `blob-service-reverse-index` table. They will be needed in subsequent diffs. This is mostly the same approach as in D5693 (parent diff). [Link to the C++ counterpart](https://github.com/CommE2E/comm/blob/32d6628a1db51c4f1432fa471bf6508cd331f7d7/services/blob/src/DatabaseManager.cpp) Part of [[ https://linear.app/comm/issue/ENG-2300/access-s3-and-dynamodb-in-blob-service | ENG-2300 ]] Depends on D5693

Implemented methods for managing the `blob-service-reverse-index` table. They will be needed in subsequent diffs. This is mostly the same approach as in D5693 (parent diff). [Link to the C++ counterpart](https://github.com/CommE2E/comm/blob/32d6628a1db51c4f1432fa471bf6508cd331f7d7/services/blob/src/DatabaseManager.cpp) Part of [[ https://linear.app/comm/issue/ENG-2300/access-s3-and-dynamodb-in-blob-service | ENG-2300 ]] Depends on D5693