feat(media): media client rewrite and widget progress bar

[Video-Nomad]

Changed main.py qasync init to proper one from this example and other related changes:

• Initialize qasync loop immediately.
• Fixes "no running loop" error in various __init__ scenarios.
• Adjust controller.py exit and reload logic for qasync event.
• Added custom QApplication subclass to hold loop and close_event.
• CLI server adjustments to fix yasb hanging on exit.
• Added QSingleton metaclass that works with QObjects.

WindowsMedia rewrite and optional on-widget progress bar:

• Added optional progress bar to media widget + docs.
• Progress bar can be aligned top, center or bottom. Can be styled from css.
• Full rewrite of WindowsMedia client to use new qasync loop.
• Partial refactor of media widget to use new dataclass from new WindowsMedia client.
• Hide progress bar and progress slider if duration is too short (<=0) or too long (> 7 days).
• Moved to dedicated logger in media widget.

Better session tracking:

• Multiple sessions should now be properly synchronized even when switching between them.
• All sessions are tracked so their playback position is stable.
• YouTube and YouTube Music has a bug where they report stale data under some circumstances. Not related to YASB or Windows API.

Progress bar under the label:

Progress bar config example:

  media:
    options:
      progress_bar:
        enabled: true        # Whether to enable the progress bar on the widget.
        alignment: "bottom"  # The alignment of the progress bar inside the widget container. Can be "top", "bottom", or "center".

Styling example:

.media-widget .progress-bar {
    max-height: 2px;
    background-color: transparent;
    margin-left: 5px;
    border: none;
}

.media-widget .progress-bar::chunk {
    background-color: #0078D477;
    border-radius: 2px;
}

Additional notes:
Due to the change in main.py init, closing the app is now done by setting the asyncio event:

app = QApplication.instance()
if isinstance(app, YASBApplication):
    if app.loop and app.close_event:
        app.loop.call_soon_threadsafe(app.close_event.set)