Enable use of per-year XBRL metadata in FERC Form 1 Transforms

[cmgosnell]

In the post-sqlite Extract and the frec1 transform, integrate year-by-year metadata. This will involve integrating report_year's into each metadata and in all of the places that we are currently using the metadata, we'll need to add a layer of dealing with multiple years. Presumably, we can assume anything that we have been applying retroactively to the dbf data will use the first year of xbrl's metadata.

[cmgosnell]

this is no longer relevant because every year's metadata is now being merged.