Allow triggering of playback on available Emby / Jellyfin devices

[markjbear]

Description

We have a very large library with search pains inside of Emby, and I wanted to make a way to trigger playback on our Apple TVs from within Jellyseerr. This is possible via the API, so I've put together a prototype that meets my needs (hacky mod of the PlayButton, but the API is reusable):
https://github.com/markjbear/jellyseerr/pull/4/files

Desired Behavior

Rather than only being possible to trigger playback on the device using Jellyseerr, it should be possible to start playing something on an available device.

Additional Context

This could be expanded to become part of the current play button dropdown, with perhaps a setting in the user settings to choose default playback device - current device (current behaviour) or [ select box to pick an available device from the Emby API i've used ]

Code of Conduct

• I agree to follow Jellyseerr's Code of Conduct

[gauthier-th]

Feel free to open a pull request to implement this.