Automatically populate the contacts widget via [YellWOWPages](yellow.wownero.com/). One may still add custom contacts - they will get saved normally like before.

Requires https://git.wownero.com/wowlet/wowlet-backend/pulls/17

![https://i.imgur.com/EYa1BBf.png](https://i.imgur.com/EYa1BBf.png)

Adds some new CLI arguments

- `backend-host`
- `backend-port`
- `backend-tls`

They refer to wowlet-backend

src/mainwindow.cpp

@@ -303,6 +303,7 @@ MainWindow::MainWindow(AppContext *ctx, QWidget *parent) :
 
     // Contacts
     connect(ui->contactWidget, &ContactsWidget::fillAddress, ui->sendWidget, &SendWidget::fillAddress);
+    connect(m_ctx, &AppContext::yellowUpdated, ui->contactWidget, &ContactsWidget::loadYellowPages);
 
     // Open alias
     connect(ui->sendWidget, &SendWidget::resolveOpenAlias, m_ctx, &AppContext::onOpenAliasResolve);
@@ -632,6 +633,7 @@ void MainWindow::onWalletOpened(Wallet *wallet) {
 
     // contacts widget
     ui->contactWidget->setModel(m_ctx->currentWallet->addressBookModel());
+    ui->contactWidget->loadYellowPages();
 
     // coins page
     m_ctx->currentWallet->coins()->refresh(m_ctx->currentWallet->currentSubaddressAccount());