Additional CSS Class(es) not working on Navigation Block

[phpbits]

Describe the bug
Adding Additional CSS Class(es) on Navigation block isn't reflecting on the editor and only added on the frontend. While on the Navigation link, adding custom classes were not applied on both editor and frontend. Thanks!

[pagelab]

I was able to reproduce this using Gutenberg version 7.3.0. Related: #18629

[roo2]

I had a look at fixing this, there are two issues:

1. The Navigation Block's Additional CSS Class(es) are not rendered in the editor.
   ** The addisional CSS Classes are rendered on the live page correctly [x]
   ** This one is very easy to fix but I think the impact is very low since custom CSS is not applied in the editor anyway
2. Navigation Link components do not have their Additional CSS Class applied at all
   ** this is much more involved to fix, I looked into packages/block-library/src/navigation/index.php but it looks like the Navigation Link's Additional css class is currently passed in to this function.

For people coming from google, a workaround would be to style the Navigation Link's using e.g. nth child selectors.

[draganescu]

Hi @phpbits can you take a look at #20076 and let me know if it solves this as expected?

[phpbits]

@draganescu Tested and seems to be working fine. Custom classnames are being added. Thanks!