Use eslint-plugin-cypress to simplify defining Cypress globals

[chrisvfritz]

What problem does this feature solve?

We currently define Cypress globals explicitly in an .eslintrc for the test/e2e folder, which requires maintaining an independent list of globals Cypress might introduce in the future.

What does the proposed API look like?

Using eslint-plugin-cypress, we can simplify this to:

module.exports = {
  plugins: ['cypress'],
  env: {
    'cypress/globals': true
  }
}