peer: decorate delivery addr w/ internal key

In this commit, we move to add the internal key to the delivery addr. This way, we give the aux chan closer the extra information it may need to properly augment the normal co-op close process.

lntest/mock/walletcontroller.go

@@ -78,9 +78,8 @@ func (w *WalletController) ConfirmedBalance(int32, string) (btcutil.Amount,
 func (w *WalletController) NewAddress(lnwallet.AddressType, bool,
 	string) (btcutil.Address, error) {
 
-	addr, _ := btcutil.NewAddressPubKey(
-		w.RootKey.PubKey().SerializeCompressed(), &chaincfg.MainNetParams,
-	)
+	pkh := btcutil.Hash160(w.RootKey.PubKey().SerializeCompressed())
+	addr, _ := btcutil.NewAddressPubKeyHash(pkh, &chaincfg.MainNetParams)
 	return addr, nil
 }