Fail if maximum weight is too large

Our max weight check in CreateTransaction only worked if the transaction
was fully signed. However if we are funding a transaction, it is
possible that the tx weight will be too large for a standard tx. In that
case, we should also fail. So we use the tx weight returned by
CalculateMaximumSignedTxSize and check against the limit for those
transactions.

src/wallet/wallet.cpp

@@ -3068,7 +3068,8 @@ bool CWallet::CreateTransactionInternal(
         tx = MakeTransactionRef(std::move(txNew));
 
         // Limit size
-        if (GetTransactionWeight(*tx) > MAX_STANDARD_TX_WEIGHT)
+        if ((sign && GetTransactionWeight(*tx) > MAX_STANDARD_TX_WEIGHT) ||
+            (!sign && tx_sizes.second > MAX_STANDARD_TX_WEIGHT))
         {
             error = _("Transaction too large");
             return false;