Change Input to not suggest right away, but to wait for an edit

See Textualize#3811.

src/textual/widgets/_input.py

@@ -519,6 +519,7 @@ def _on_focus(self, _: Focus) -> None:
         if self.cursor_blink:
             self._blink_timer.resume()
         self.app.cursor_position = self.cursor_screen_offset
+        self._suggestion = ""
 
     async def _on_key(self, event: events.Key) -> None:
         self._cursor_visible = True