Implement CRC-32 Checksum logic for Deletion Vectors

[Tishj]

We recently added support for the https://iceberg.apache.org/puffin-spec/#deletion-vector-v1-blob-type delete format At the end of this deletion vector blob is a CRC-32 checksum, from the spec:

A CRC-32 checksum of the magic bytes and serialized vector as 4 bytes, big-endian

We currently ignore the checksum in its entirety, we should at some point implement this checksumming logic to verify the correctness of the deletion vector blob.