Function id_to_output_on_chain 

pub fn id_to_output_on_chain(
    db: &BlockchainDatabase,
    id: &PreRctOutputId,
    get_txid: bool,
    tx_ro: &Snapshot,
    tapes: &TapesReadTransaction<'_>,
) -> DbResult<OutputOnChain>

Map an PreRctOutputId to an [OutputOnChain].

Note that this still support RCT outputs, in that case, PreRctOutputId::amount should be 0.