fix(types): add walkUniversals declaration

[marcalexiei]

walkUniversals is not declared in package types.

This PR adds the relevant declaration and provide few additional improvements:

• uniform d.ts function with callback style
• use typescript satisfies instead of as to check property typings

[alexander-akait]

Let's write it in one line as was written before

[marcalexiei]

I have update the code style. Let me know if you need further adjustments!

[alexander-akait]

Thanks