[sidecar] Wrong TX index assignment

[liran-funaro]

In the relay we assign to the TX index map as follows. But this uses the txIndex from the list of valid TXs, instead of the block's TX index.
This works because all our tests have either all correct TXs or all incorrect.

for txIndex, tx := range mappedBlock.block.Txs {
	if _, loaded := r.txIDToBlkNum.LoadOrStore(tx.Id, blockNum); !loaded {
		logger.Debugf("Adding txID [%s] to in progress list", tx.GetId())
		mappedBlock.withStatus.txIDToTxIndex[tx.Id] = txIndex
		continue
	}
	logger.Debugf("txID [%s] is duplicate", tx.GetId())
	promutil.AddToCounterVec(r.metrics.transactionsStatusReceivedTotal, []string{
		protoblocktx.Status_ABORTED_DUPLICATE_TXID.String(),
	}, 1)
	mappedBlock.withStatus.pendingCount--
	mappedBlock.withStatus.txStatus[txIndex] = validationCode(protoblocktx.Status_ABORTED_DUPLICATE_TXID)
	dupIdx = append(dupIdx, txIndex)
}