Change tootctl to use inline parallelization instead of Sidekiq (#11776)

- Remove --background option
- Add --concurrency(=5) option
- Add progress bars

app/models/media_attachment.rb

@@ -129,6 +129,7 @@ class MediaAttachment < ApplicationRecord
   scope :unattached, -> { where(status_id: nil, scheduled_status_id: nil) }
   scope :local,      -> { where(remote_url: '') }
   scope :remote,     -> { where.not(remote_url: '') }
+  scope :cached,     -> { remote.where.not(file_file_name: nil) }
 
   default_scope { order(id: :asc) }