Show scorecard pages for former legislators

[dscush]

The way the scorecard is currently coded, after a legislator is leaves office, they disappear from the website. In reality, however, they don't always disappear from politics. When a former legislator runs for another office, it would be helpful to be able to access their old scorecard page.

There will be a bit of UX work to find a way to include this in the site. The backend work of adding the former legislators to the data processing scripts won't be too crazy. When we get the current legislators from Open States right now, we filter for memberOf the House/Senate organization ID. To get former legislators, we can use everMemberOf which gives you both current and retired members, and just match them against our old scorecard spreadsheets. Playing around in the Open States graphql web client will help determine the exact query we want.