Resurrect ebudget scraper

[ian-r-rose]

We have an old scraper for the CA ebudget site that has been disabled for a while here. This gets us budgets and budgeted positions (as opposed to actual headcount, cf #596 ) per department, per year. We want to do the following:

1. Resurrect it so that it works again. Hopefully this is as simple as turning it back on, but there may be some tweaks needed.
2. Extend it so that it targets multiple years, going back in time. This can be based on the logical execution date in the Airflow context.
3. Do a backfill going back as far as the ebudget site does.

For the moment we can focus on the enacted budget. There may be interest in the proposed and may-revise versions later, but those can be handled separately.