Allow Icon / Custom component for thumb in Switch component

### Description

Hey!
Currently, other than its color, it's not possible to change the thumb component in the Switch component. It would be great if we could define a custom component like icons that is rendered instead of the default thumb as it is now.
There is a hacky workaround where, for example, an icon can be rendered above the thumb. However, it won't be animated by default but only rendered after the switch animation is complete.

### Problem Statement

Many modern designs of switch components include custom thumbs or at least icons within the default thumb which is why it should be easily addable in NB

### Proposed Solution or API

-

### Alternatives

_No response_

### Additional Information

_No response_