Add tie result for approval

[ArendPeter]

Description

This updates the approval results page to sometimes indicate that the election is tied instead of showing a winner

Here are the specific updates

• Add election setting for breaking ties randomly
• Adjust results title to show ties
• Refactor tabulator to avoid managing offsets on an array
• Refactor tabulator to always sort candidates and break ties randomly (the break ties randomly setting is only used by the frontend)
• Refactor tabulator with SingleWinnerApproval sub-method

Here's some follow up tasks

• filter random tie break out of the detailed steps if random tiebreaker isn't enabled
• add support for random tie breaker in the settings (it's currently locked to disabled)

Screenshots / Videos (frontend only)

Related Issues

related #415

[mikefranze]

Looks good, but I'm wondering if we should also include ties that occur in each round in the round_results. That should also be an array since you could have multiple ties in STAR.

[ArendPeter]

Looks good, but I'm wondering if we should also include ties that occur in each round in the round_results. That should also be an array since you could have multiple ties in STAR.

I added the ties to the logs within the round results, but not as an additional field. I'd be open exposing it's own field in the future, but in general I think it's better to keep the output simpler and limit the fields to those that we expect the frontend to consume.

[mikefranze]

Looks good