allow chaining polymorphic components

[mayank99]

Changes

This updates the polymorphic implementation so that the as prop can accept an array of components. Each of the components in the array will be rendered sequentially, forming a chain of components that build upon each other.

This array implementation is completely hidden from users, since they should not be passing arrays into as. Think of it as an internal feature to help to us compose multiple primitives together.

This is needed to address a TODO item from #2021 (see thread). We are now able to use ButtonBase and ListItem together.

(Also related but not fully addressed: #2135 (comment)).

Further thoughts: The as prop seems to have fallen out of fashion in the React world. The alternatives are asChild and render props, both of which allow chaining components without any TS issues. However, it is too late to change our component API.

Testing

Pending.

Docs

N/A