Transform `f1_othr_reg_liab` xbrl + dbf

Table Notes

Has both instant and duration tables in XBRL
Instant table has "end of last year" and "end of this year"
Terrible disaster of a shared index column other_regulatory_liability_axis which is a freeform string.
Data columns describe both increase and decrease in "other" regulatory liabilities over the course of the year.
Category of liability is not controlled. Freeform description + a column with a list of FERC account numbers.
DBF & XBRL have the same (lack of) structure.

Because the duration table contains deltas, we should probably create starting / ending balances using the values in the instant table
Aggregation will not really be possible without a bunch of tedious manual categorization because the categories are freeform strings.
Comparison across utilities and years will also probably be a nightmare.
Some categories include FERC Account numbers but many do not, and they're poorly standardized so this isn't super helpful.
No row-mapping to be done -- it's all just a list of descriptions.
There is an "order number" column in here suggesting they are actively preserving the ordering of the rows, which is important in this kind of freeform table.
May want to try and pull out the TOTAL row from each filing.