TypeScript e2e tests

[rmccrear]

This PR converts the e2e tests to TypeScript and adds basic checks for the proof results.

To run, use:

yarn
yarn test
yarn test:e2e-ui
yarn test:e2e-zkp # will take a long time to complete and may fail if you run out of memory.

It's also possible to run headless by changing this in e2e-dl-zkp.test.ts

browser = await puppeteer.launch({
  // headless: true,
  headless: false,
  slowMo: 100
});

to this

browser = await puppeteer.launch({
  headless: true,
  // headless: false,
  // slowMo: 100
});