Get EIA861 short form data into db tables

[aesharpe]

The EIA861 Form has a short version for entities reporting less than 100K MWh of power. In 2019 the responses to the short form were included/distributed throughout the other tables with a boolean column called short_form. All other years since the inception of the short form (2012) utilize a separate short_form csv. Right now, the short form csv is getting extracted but not included/distributed throughout the other tables meaning that there is only short form data for 2019.

This is largely because the short form data is reported differently. For example, the sales data is not separated by customer class and the DSM / net metering data is just a boolean rather than detailed information.

We should figure out:

1. Why / how the 2019 data got integrated. Is it possible to replicate with other years??
2. What to do with the existing short form data - right now it's not even getting published to the database. Maybe we should at least publish it as it's own table?

Also, the EIA861 documentation page could use some sprucing up. See https://docs.google.com/document/d/1v_5yzyzizNK_xmuCT7_wHTQVSQy-XQ7r8WDEQFZbEEs/edit for more details.