This ensures that UTXO unserialization errors abort the node, and does
not cause a consensus divergence.
A valid UTXO is created and shared between two nodes. The raw database
entry is then deliberately modified on one node so it can no longer be
deserialized. When the other node spends that UTXO and mines a block,
the node with the unserializable entry must abort during block connection
rather than silently treating the coin as absent and marking the block
BLOCK_FAILED_VALID, which would cause it to permanently diverge from the
network's best chain.
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