Refactor: Story queue: Extract processStory

Move the process-item part of the queue outside
of the queue loop, mainly to gain insight into
making a better design.
Add a simple queue consumer

Prepare our move to a more-stable,
story-queueing model, by introducing
this simple queue consumer.
Refactor: Use queue consumer for adding stories

Use our generic queue consumer for adding stories
to the database, and remove our previous queue
implementation.