Report fees for onchain transactions that split UTXOs

[giancarloGiuffra]

Onchain transactions that only pay to addresses controlled by the node are not reported. From the point of view of accounting this seems correct. However, the paid onchain fees are not reported either. These fees affect the onchain balance of the node and thus should be included in the audit report.

Zero-amount onchain transactions are explicitly excluded here: https://github.com/lightninglabs/faraday/blob/12b66ac753c92d0c237ad2523f0ec93c82898f92/accounting/entries.go#L245-L261

I agree that any sweep transaction of the remote counterparty should not be included since it was the remote counterparty that paid the fees. However, that condition is also excluding the transactions I described above.