WIP: Docker Raddar/Sonarr/Bazarr stack

[publicarray]

Motivation: With DSM 7.0 we can create docker packages and one combination that appears to be asked for often is the *arr stack. It is early days but even if this doesn't work, it can be used as a stepping stone to build other docker packages.

FYI: I increased the port number by 1 temporarily as not to conflict with other installations. (except Plex)

One behaviour I don't like about Synology's implementation; even when I tag specific image versions, Docker still removes all images and redownloads them on a package update/install. This is just a bit over 1GB every time.

@Bokkoman thanks for your feedback and in general for the docker-compose template/guide

Checklist

• [ ] Build rule all-supported completed successfully
• [x] Package upgrade completed successfully
• [x] New installation of package completed successfully (@Bokkoman reports it fails)
• [ ] Usability Tests:
  • [x] Raddar
  • [x] Sonarr
  • [x] Bazarr
  • [ ] Plex - can't authorise, probably because I got the syntax wrong for the allowed local IPs - Plex claim is useless since it expires in 4 minutes, and it takes docker significantly longer to have everything up by then.