extract-component package

Refactoring task to extract a portion of JSX as a new component.

TODO

x Prettier indentation on both removed and inserted text / Look for var refs and transform to props - done-ish, currently looks only for MemberExpression names would be better if became:

		const Component = ({ src }) => (
		<Image src={src}/>
	  )

	although this would introduce complexity and probably new edge cases

• grab jsx component imports
• restore focus to active editor on modal close
  • this should be working, not sure why it isn't
• save the new component file immediately?
• add new import last?
• Allow for leaving children in place, only extracting wrapping element as component
• Leave children by default, by UI option, or by separate command?