qt: Fix tab order in send and receive tab

src/qt/bitcoinamountfield.cpp

@@ -116,7 +116,8 @@ bool BitcoinAmountField::eventFilter(QObject *object, QEvent *event)
 QWidget *BitcoinAmountField::setupTabChain(QWidget *prev)
 {
     QWidget::setTabOrder(prev, amount);
-    return amount;
+    QWidget::setTabOrder(amount, unit);
+    return unit;
 }
 
 qint64 BitcoinAmountField::value(bool *valid_out) const

src/qt/forms/receivecoinsdialog.ui

@@ -245,6 +245,9 @@
         <property name="contextMenuPolicy">
          <enum>Qt::CustomContextMenu</enum>
         </property>
+        <property name="tabKeyNavigation">
+         <bool>false</bool>
+        </property>
         <property name="sortingEnabled">
          <bool>true</bool>
         </property>
@@ -312,8 +315,8 @@
   <tabstop>reqAmount</tabstop>
   <tabstop>reqMessage</tabstop>
   <tabstop>reuseAddress</tabstop>
-  <tabstop>clearButton</tabstop>
   <tabstop>receiveButton</tabstop>
+  <tabstop>clearButton</tabstop>
   <tabstop>recentRequestsView</tabstop>
   <tabstop>showRequestButton</tabstop>
   <tabstop>removeRequestButton</tabstop>

src/qt/sendcoinsdialog.cpp

@@ -325,9 +325,10 @@ QWidget *SendCoinsDialog::setupTabChain(QWidget *prev)
             prev = entry->setupTabChain(prev);
         }
     }
-    QWidget::setTabOrder(prev, ui->addButton);
-    QWidget::setTabOrder(ui->addButton, ui->sendButton);
-    return ui->sendButton;
+    QWidget::setTabOrder(prev, ui->sendButton);
+    QWidget::setTabOrder(ui->sendButton, ui->clearButton);
+    QWidget::setTabOrder(ui->clearButton, ui->addButton);
+    return ui->addButton;
 }
 
 void SendCoinsDialog::setAddress(const QString &address)