Unify vote types

Summary

Currently, there are multiple vote types defined for what amount to one vote type. For instance, we have an "up" type and a "down" type rather than an "updown" type. This leads to certain inefficiencies, like having to manually calculate the total/net votes for an entity by getting the total up votes and total down votes and then doing math. The Voting API does this out of the box if you define one "updown" type that has positive and negative votes. (It already calculates total and net within a vote type.)

Proposed solution

Reduce the vote types to just "updown" and "fivestar", with the values of the votes being the differentiator.