Default values for props are not always extracted

The default value for props does not always seem to get extracted by `extract-react-types`.

One place where this is very visible is https://atlassian.design/components/button/code which has no default value information (despite having default values for many of the props).

As @danieldelcore indicated on Slack this is likely because:
> I suspect it only pulls defaults off a component from the Component.defaultProps property or via static defaultProps rather than destructured function args

It would be great if `extract-react-types` could support extracting default values for props that are defined through default values on destructured function args 😄