Broken, half-done support for halo2 batch verification

[dconnolly]

Somewhat blocked on functions and data in orchard types being private: https://discord.com/channels/809218587167293450/876655911790321684/993595666557325452

Motivation

Specifications

Designs

Solution

Review

Reviewer Checklist

• [ ] Code implements Specs and Designs
• [ ] Tests for Expected Behaviour
• [ ] Tests for Errors

Follow Up Work