Dont ask storage to delete inlined blobs

Currently when using a sql index, it is possible to store small blobs inline in the database. In common setups, these result in the majority of blobs. In the current cleanup script, we don't evaluate if the blob is inlined before requesting to delete it from the underlying storage. This leads to many blobs being requested for delete that do not actually exist in the underlying storage.

With the change, mark_n_bytes_as_deleted is updated to return two lists, the ones inlined and the ones not. This allows the cleaner to immediately remove the small entries (avoiding many deleted=true records in the database), and can provide a smaller list to the actual storage.