Add support for JS notation styles to styled API

## Describe the feature

Currently the `styled` API accepts literal tagged template literals which accepts CSS naming scheme for styles.

I think we could also extend the API to accept valid CSS styles in JavaScript notation too!

## Motivation
1. React Native devs would appreciate it.
2. Some people like styling in JS way.
3. More options for people to choose.

## Possible implementations

Something similar to how emotion does,

```
const StyledHeading = styled('h1')(() => ({
fontSize: '24px'
});
```

`props` or `theme` from a `ThemeProvider` can be passed to the callback function for easy access.

```
const StyledHeading = styled('h1')(({ theme, color }) => ({
fontSize: '24px',
...( color && { color })
});
```

## Related Issues