[FR] Support Overseerr

[JosefWN]

Is your feature request related to a problem? Please describe.
Overseerr is a slick unified UI sitting on top of Sonarr and Radarr, tightly integrated with Plex. Sort of analogous to Jackett/Prowlarr but for media discovery and download rather than for configuration.

Describe the solution you'd like
Add an Overseerr service: https://overseerr.dev/
There's a linuxserver image as well: https://hub.docker.com/r/linuxserver/overseerr

Describe alternatives you've considered
Haven't seen any comparable alternatives.