Add play pause controls to taskbar

[Kethku]

On windows often apps will add small controls to the taskbar. It would be awesome if psst added similar controls.

Note: I think this may require some upstream changes

[jpochyla]

Sounds good! I'm not very familiar with the windows customs, something like this from the API docs? Is it conventional to provide both a taskbar extension and a media player API integration (that we now support through the Souvlaki library)?

[Kethku]

Heres what they look like. Yes they are added even when media player api integration is also used.

[Kethku]

Added an upstream suggestion here: Sinono3/souvlaki#14. I think this feature makes the most sense to add to the souvlaki crate