- Due to https://github.com/exAspArk/batch-loader/pull/32,
we  changed BatchLoader.for into BatchLoader::GraphQL.for
- since our results are wrapped in a BatchLoader::GraphQL,
calling `sync` during authorization is required to get real object
- `graphql` now has it's own authorization system.  Our
`authorized?` method conflicted and required renaming

Add new query for Groups, with new
GroupType and NamespaceType

By specifying `key`, we get a different lazy batch loader for each
repository, which means that accessing a lazy object from one repository
will only result in that repository's objects being fetched, not those
of other repositories, saving us some unnecessary Gitaly lookups.

Partially addresses #47424.

- All definitions have been replaced by classes:
  http://graphql-ruby.org/schema/class_based_api.html
- Authorization & Presentation have been refactored to work in the
  class based system
- Loaders have been replaced by resolvers
- Times are now coersed as ISO 8601