community/docker: upgrade to 20.10.1

Upstream 'docker/docker-ce' is no longer maintained, so we now pull docker/cli and moby/moby independently.

Removed docker-vim subpackage as authoritative 'dockerfile.vim' is maintained in vim source.

For more information, see: https://docs.docker.com/engine/release-notes/#20101

Resolves #12223 (closed)