Scrape Campaign Finance Data

## Summary
As part of the Legislator Profile project, we want to be able to show users Campaign Finance data associated with Legislators.

This is the backend data necessary for the `Finance` tab on the Legislator Profiles.

(Campaign Finance data has also long been desired for other use cases - we recently pulled it for specific Ballot Questions - so this is likely more broadly useful than Legislator Profiles).

## Success Criteria
- [ ] Investigate OCPF data to assess availability (how frequently it updates and how to map to specific legislator/candidates)
- [ ] Scraper that pulls Campaign Finance data from OCPF into a Firestore Collection
- [ ] Need to be able to query by Legislator for the Legislator Profiles

## Additional Links
- OCPF (Office of Campaign and Political Finance) data: https://www.ocpf.us/Data/Downloads
- Design for Legislator Profile: https://maple-leg-profiles.netlify.app/