wallet: create tx, log resulting coin selection info

Useful for understanding what is going on internally
when the software is running. Debug issues, and provide
more accurate feedback to users.

Author: furszy

src/wallet/spend.cpp

@@ -1263,6 +1263,7 @@ static util::Result<CreatedTransactionResult> CreateTransactionInternal(
     // accidental reuse.
     reservedest.KeepDestination();
 
+    wallet.WalletLogPrintf("Coin Selection: Algorithm:%s, Waste Metric Score:%d\n", GetAlgorithmName(result.GetAlgo()), result.GetWaste());
     wallet.WalletLogPrintf("Fee Calculation: Fee:%d Bytes:%u Tgt:%d (requested %d) Reason:\"%s\" Decay %.5f: Estimation: (%g - %g) %.2f%% %.1f/(%.1f %d mem %.1f out) Fail: (%g - %g) %.2f%% %.1f/(%.1f %d mem %.1f out)\n",
               current_fee, nBytes, feeCalc.returnedTarget, feeCalc.desiredTarget, StringForFeeReason(feeCalc.reason), feeCalc.est.decay,
               feeCalc.est.pass.start, feeCalc.est.pass.end,