fix(pretty-format): Handle empty string children in React same as `react-test-renderer`#14470

SimenB merged 3 commits intojestjs:mainjestjs/jest:mainfrom

SimenB:align-pretty-format-and-test-renderer-single-string-childSimenB/jest:align-pretty-format-and-test-renderer-single-string-childCopy head branch name to clipboard