Legislator Profile - Sidebar

## Summary

This issue covers the implementation of the Sidebar in the Legislator Profile. This includes three components:
- Others' Testimony on their sponsored bills
- Upcoming Hearings
- The Legislator's Biography (Editable by the legislator, similar to the `Priorities` tab information)

## Success Criteria
- [ ] Implement the Sidebar for the Legislator Profile page, including:
- [ ] Others' Testimony section - showing the most recent 3 testimonies submitted by other users on bills this Legislator sponsored
- [ ] Should link to the `Browse Testimony` page if there are more than 3 testimonies
- [ ] TODO: We may need to add an additional search option on the `Browse Testimony` page that lets us search for testimony by bill sponsor
- [ ] Fair to only consider the current general court's testimony
- [ ] Upcoming Hearings section - showing the next 3 hearings the legislator will be part of (as determined by Committee membership - if the legislator is a member of the Committee hosting the hearing, we can assume by default that they will be present)
- [ ] Can use similar logic to the "Hearings Scheduled" section of the Home Page
- [x] Legislator Biography section
- [x] Should be editable by the Legislator account associated with this Legislator (identical to how the `Priorities` Tab works)
- [x] Should have an empty state if a legislator has not updated this yet (e.g. "This legislator has not claimed their MAPLE account")

## Screenshots

Others' Testimony Section:

Upcoming Hearings Section:

Legislator Biography Section:

## Additional Links
- Mockup: https://maple-leg-profiles.netlify.app/