Convert License DB export component to worker handler

Convert the existing license DB exporter component to a worker handler. Add a scheduler change to run the handler on a similar schedule.

This component is a worker handler. See the worker design for additional information.

Diagrams

sequenceDiagram

    participant s as Scheduler
    participant w as Worker
    participant ex as Export Handler
    participant db as SQL
    participant ps as PubSub
    participant remote as Cloud Storage

    s ->> ps: Trigger Export

    ps ->> w: Poll for Message
    w ->> ex: Run

    ex ->> db: Get configuration and state

    ex ->> db: Table scan filtered by datetime

    loop Foreach Change
        ex ->> ex: Process change
    end

    ex ->> remote: Create and compress export file(s)

    ex ->> db: Update state