Allow toggling through combo box options using left/right on gamepads/keyboards

app/gui/AutoResizingComboBox.qml

@@ -50,4 +50,12 @@ ComboBox {
     popup.onAboutToHide: {
         SdlGamepadKeyNavigation.setUiNavMode(true)
     }
+
+    Keys.onLeftPressed: {
+        decrementCurrentIndex()
+    }
+
+    Keys.onRightPressed: {
+        incrementCurrentIndex()
+    }
 }