add plex support for previous and next

[guirem]

Currently, cast device playing plex media returns basic/default supported_media_commands data that does not reflect what the cast device can do/accept. In hass, the next and previous command is not available.

This PR will activate the next/previous command for plex media_player by overwriting the supported media information received by the cast device.

[emontnemery]

Why is the plex app reporting the wrong information? Is there any way to know when the app will accept next/previous and when it won't?

[guirem]

I believe it can relate to these already known issues https://github.com/home-assistant/core/issues/58888 and https://github.com/home-assistant/core/issues/49243 . Problem seems to be in google cast plex app implementation.

I tested with several type of media and configuration using official desktop player with chromecast broadcast and the device retruns the same supported media command code.

I guess next/previous won't be possible if this is a single item playing but not even sure of that as it always seem to be creating some sort of virtual playlist (plex player or via hass).

[guirem]

Hi, Any chance this change may be in a future release? @emontnemery what additional info I could provide ?

[emontnemery]

I'm closing this PR now since the review comments have not been addressed in almost two years. @guirem Please open a new PR addressing my review comments if you still want to see this functionality merged.