Improve userfriendlyness of VAServer.exe selection

• bring UI to the front and print respective hint

src/vapython/_helper.py

@@ -204,7 +204,11 @@ def find_server_executable() -> Optional[Path]:
 
             root = tk.Tk()
             root.withdraw()
+            root.attributes("-topmost", 1)
 
+            print(  # noqa: T201
+                "NOTE: A window has opened for specifying the path to the 'VAServer.exe'. This should be located in the `bin` subfolder of the respective VA directory."
+            )
             executable_raw = filedialog.askopenfilename(
                 title="Select VAServer executable",
                 filetypes=[("VAServer executable", "*.exe")],