Include LoC and Wikidata format indentification

[pwinckles]

LoC has started publishing a mapping file for their file description documents (FDDs) to their equivalent identifiers in PRONOM and Wikidata.

For files where DROID is able to make an identification, the mapping could be used to derive the corresponding FDD and QID.

That said, I browsed the mapping file this morning, and it's not as complete as you'd hope. For example, LoC designates XML 1.0 as fdd000263, but does not map it to anything. It is unclear why fmt/101 is not a match.