Support passing updater function to setState in SSR mode

[mdebbar]

Passing an updater function to setState() is something that React supports and people use this pattern. Fortunately, supporting that pattern in react-apollo's SSR mode is simple, so I added it and covered it with a test.

Checklist:

• If this PR is a new feature, please reference an issue where a consensus about the design was reached (not necessary for small changes)
• Make sure all of the significant new logic is covered by tests
• If this was a change that affects the external API used in GitHunt-React, update GitHunt-React and post a link to the PR in the discussion.