printRelayQuery returns {text,variables} - (OSS version)

[josephsavona]

Changes babel-relay-plugin to output the type names for complex (non-scalar) types, and updates the OSS variant of printRelayQuery to return {text,variables} instead of only the query text. This corresponds to the change in b5c1512.

An example of the output is as follows:

{
  text: `
    query UnknownFile($0:SearchInput) {
      search(query:$0) {
        ...
      }
    }
  `,
  variables: {
    0: {q: 'foo'},
  },
}

[josephsavona]

I'll split the babel plugin and src/ changes into separate PRs