rolling_tv_channel.py: Add per-user context for playlist generation

[jedinjapan]

In what file should the feature be added?
"rolling_tv_channel.py"

What is the feature request?
To expand on the existing feature set by allowing the admin to feed a user parameter manually or via Tautulli automation in order to give context for where to pull the On Deck status from, and where to share the resulting playlist. This would allow each "channel" to be tailored to the user. "90s TV - Alex", "90s TV - Shane". By doing so you could maintain multiple "channel" playlists with each user only controlling the watch state of their own, while the admin can pre-populate them all to get them started.