/admin/freshmen Times Out

The `/admin/freshmen` route times out when there are lots of freshmen (~300 in prod, much more in dev). It works running locally with only two freshmen, so the issue seems to be tied to the amount of data that's being processed and rendered.

My guess is that pagination or lazy loading would solve this.

For pagination, I recommend the [flask sqlalchemy paginate function](https://flask-sqlalchemy.palletsprojects.com/en/2.x/api/?highlight=paginate#flask_sqlalchemy.BaseQuery.paginate).

Lazy loading is a little more complex, and might need api changes. TL;DR: rather than loading up all the freshmen, then rendering the page, the lazy load version would defer the data loading till after the page is rendered, so the user could interact with the page while it's still being populated. (I'm probably not using the term quite correctly here, but it's close enough to the idea)