add simple internal notification popup,

refactor MessageDialog

electrum/gui/qml/components/main.qml

@@ -169,62 +169,13 @@ ApplicationWindow
     property alias messageDialog: _messageDialog
     Component {
         id: _messageDialog
-        Dialog {
-            id: dialog
-            title: qsTr("Message")
+        MessageDialog {}
+    }
 
-            property bool yesno: false
-            property alias text: message.text
-
-            signal yesClicked
-            signal noClicked
-
-            parent: Overlay.overlay
-            modal: true
-            x: (parent.width - width) / 2
-            y: (parent.height - height) / 2
-            Overlay.modal: Rectangle {
-                color: "#aa000000"
-            }
-
-            ColumnLayout {
-                TextArea {
-                    id: message
-                    Layout.preferredWidth: Overlay.overlay.width *2/3
-                    readOnly: true
-                    wrapMode: TextInput.WordWrap
-                    //textFormat: TextEdit.RichText // existing translations not richtext yet
-                    background: Rectangle {
-                        color: 'transparent'
-                    }
-                }
-
-                RowLayout {
-                    Layout.alignment: Qt.AlignHCenter
-                    Button {
-                        text: qsTr('Ok')
-                        visible: !yesno
-                        onClicked: dialog.close()
-                    }
-                    Button {
-                        text: qsTr('Yes')
-                        visible: yesno
-                        onClicked: {
-                            yesClicked()
-                            dialog.close()
-                        }
-                    }
-                    Button {
-                        text: qsTr('No')
-                        visible: yesno
-                        onClicked: {
-                            noClicked()
-                            dialog.close()
-                        }
-                    }
-                }
-            }
-        }
+    property alias notificationPopup: _notificationPopup
+    Component {
+        id: _notificationPopup
+        NotificationPopup {}
     }
 
     Component.onCompleted: {