Add pictorial ids, script for 118th Congress

Adds ids mapping to GPO's Pictorial Member Guide
pictorialapi.gpo.gov

This PR includes ids for all members of 118th Congress. It may also work
for historical files -- at least going back to 110 -- but I have not
included that work here, as it requires manual fixes and I imagine most
interest is in current membership.

Closes unitedstates#942