Add a close button for dialogs.

gpt4all-chat/qml/MyDialog.qml

@@ -0,0 +1,33 @@
+import QtCore
+import QtQuick
+import QtQuick.Controls
+import QtQuick.Controls.Basic
+import QtQuick.Dialogs
+import QtQuick.Layouts
+
+Dialog {
+    id: myDialog
+    background: Rectangle {
+        width: parent.width
+        height: parent.height
+        color: theme.backgroundDarkest
+        border.width: 1
+        border.color: theme.dialogBorder
+        radius: 10
+    }
+
+    MyToolButton {
+        x: 0 + myDialog.width - myDialog.padding - width - 15
+        y: 0 - myDialog.padding + 15
+        z: 300
+        visible: myDialog.closePolicy != Popup.NoAutoClose
+        width: 30
+        height: 30
+        padding: 0
+        source: "qrc:/gpt4all/icons/close.svg"
+        fillMode: Image.PreserveAspectFit
+        onClicked: {
+            myDialog.close();
+        }
+    }
+}