Updated tkvlc.py example

- Find libtk in yet another place in Python 3.11+.

- Fixed spurious message "not in fullscreen state" on macOS.

- Ignore OnConfig events while toggling to/from fullscreen (on macOS) and while tweaking the aspect ratio of the video panel.

- Right-click in the video panel to post the Video menu on macOS.

- Tested with the latest VLC 3.0.21 and python vlc.py on Windows 11 and macOS 14.7.3 Sonoma (AppleSi and X86_64).

Author: mrJean1