Add support for React server components

Using the Highlight component inside a component that is not marked with "use client" will throw the following error:

```
TypeError: Super expression must either be null or a function, not undefined
at _inherits (webpack-internal:///(rsc)/./node_modules/react-highlight/lib/index.js:43:15)
at eval (webpack-internal:///(rsc)/./node_modules/react-highlight/lib/index.js:56:5)
at eval (webpack-internal:///(rsc)/./node_modules/react-highlight/lib/index.js:120:2)
at (rsc)/./node_modules/react-highlight/lib/index.js (D:\XXX\.next\server\vendor-chunks\react-highlight.js:50:1)
```

This is happening because the `Highlight` component uses the lifecycle events `componentDidMount` and `componentDidUpdate`, which can't be used in RSC.

It would be interesting to add basic support for RSC, for example by providing a fallback component that just renders a `pre` element with no highlighting. Otherwise, users using this library and RSC will encounter this error which can be hard to debug.