Call multiple years at once for generating FBAs

[bl-young]

Some datasets contain time series data from a single source. Current approach requires that for every year of FBA desired, the data source must be called and parsed in a loop which in many cases is unnecessary. The final FBA can be subset just prior to saving to maintain FBAs for each year while only sourcing the dataset once.

[bl-young]

enabled via FBA parameter call_all_years: True

To be effective, requires that the FBA data source script handles multiple years at once (i.e., does not filter by year).