ui: scroll newly added items into view

pqcli/ui/custom_list_box.py

@@ -0,0 +1,14 @@
+import typing as T
+
+import urwid
+
+
+class CustomListWalker(urwid.SimpleFocusListWalker):
+    def append(self, item) -> None:
+        super().append(item)
+        self.set_focus(len(self) - 1)
+
+
+class CustomListBox(urwid.ListBox):
+    def __init__(self, widgets: T.List[urwid.Widget]) -> None:
+        super().__init__(CustomListWalker(widgets))