CAKE-294 | wallet saved when accounts and subaddresses are changed

lib/monero/monero_wallet.dart

@@ -100,8 +100,10 @@ abstract class MoneroWalletBase extends WalletBase<MoneroBalance> with Store {
 
   Future<void> init() async {
     accountList.update();
+    accountList.accounts.observe((_) async => await save());
     account = accountList.accounts.first;
     subaddressList.update(accountIndex: account.id ?? 0);
+    subaddressList.subaddresses.observe((_) async => await save());
     subaddress = subaddressList.getAll().first;
     balance = MoneroBalance(
         fullBalance: monero_wallet.getFullBalance(accountIndex: account.id),