fix(NcCheckboxRadioSwitch): improve rendering and prevent unecessary elements

[skjnldsv]

• Make the icon inert
• Do not render the content text if undefined

[ShGKme]

I don't understand... Icon span is neither focusable nor interactive anyway, does inert change anything here?

Is it an alternative or a part of #4999 ?

[emoral435]

From what I am seeing, the inert attribute would just be a preventative in case the inserted slot is indeed focusable, no? It is not a breaking change, more of a preventative one from what I gather. As of now, I do not believe it hurts to add it on

[ShGKme]

the inert attribute would just be a preventative in case the inserted slot is indeed focusable, no?

It would be an a11y issue if there was an interactive focusable and yet inert element...

[skjnldsv]

It would be an a11y issue if there was an interactive focusable and yet inert element...

That's the point, sanitising what we allow in those slots.
It also hides the element and its content from assistive technologies by excluding them from the accessibility tree. Which it should as it's a non descriptive image and should not be read or described. It's basically what aria-hidden is doing (already here), but stronger imho

Is it an alternative or a part of #4999 ?

No, It just happen that I branched it from the other PR, it will change its base branch once #4999 is merged