Draggable ReactQueryDevtools icon

[murafalizade]

ReactQueryDevtools component has position props to arrange location of tool. It would be nice if it was draggable like Next.js icon. Because in some cases, it covers important something on UI and every time changing position is quite annoying. Therefore I would like to add this feature. I am aware of that it is less prioritized idea, however I believe it brings more developer experience.

Sincerely, I am open to make this kind of changes and contribute it.