Rename Navigation Link and Submenu label classname to match other generic classnames

[tellthemachines]

What problem does this address?

#33918 added generic classnames across several blocks used inside the Navigation block, using wp-block-navigation-item__[element] as the general pattern. One classname seems to have escaped this update: wp-block-navigation-link__label, which is added to the span wrapping the text on both the Navigation Link and Submenu parent element. This classname is rendered on the Submenu even when the parent item is a button, so naming it "link" doesn't make much sense.

What is your proposed solution?

Replace wp-block-navigation-link__label with wp-block-navigation-item__label on both blocks, to match the current naming pattern.