Add shouldForwardProp method

[Pytal]

Describe the feature

A shouldForwardProp config method should be added so that custom props don't leak into the DOM.

This feature was recently added to styled-components/styled-components#3006.

Motivation

I often use custom boolean props to toggle styles but since boolean attributes are not valid in the DOM React complains about them.

shouldForwardProp would allow you to explicitly define which props should be passed to the DOM and which props are for internal use.

Related Issues

#256

[jayu]

Hey @Pytal, could you provide a code example to visualize the problem?

[Pytal]

😅 Turns out the issue was with react-spring since I wrapped a react-spring component.

Since react-spring doesn't do any prop filtering all props were passed to the DOM.