media_acquisition: migrate from jellyseerr to seerr

Created by: jedmund

Summary

• Swap image from fallenbagel/jellyseerr to ghcr.io/seerr-team/seerr
• Rename service, container, and config volume path from jellyseerr → seerr

The config directory rename (jellyseerr → seerr) in tasks/main.yml is included in the slskd PR due to an indivisible hunk. The existing config data will need to be moved on the server before deploying.