Navigation: Using different item justification on main menu and overlay menu

[carolinan]

What problem does this address?

It is a common design for themes to have a site title or logo aligned to the left, and a menu to the right (and vice versa on rtl),
This is used in Twenty Twenty-Two. This is achievable because we can justify the menu items.

But when we justify the menu items, the overlay use the same justification. There is no way to have a right aligned main menu
and then use left aligned menu items on the overlay (Not without additional CSS).

What is your proposed solution?

Add a way to use different justifications for different menu views.

[jasmussen]

Related, #34514

Flow wise, it seems like the contents of the modal could be edited in isolation, a bit like how template parts can be.

[maffi-git]

I also think this should go into a separate template. There are just too many things missing still.
Can't change icon, icon-paddings/margin, color etc.
Can't change breakpoint
I'm just asking myself, how do we let Users edit this?
Two ways come to my mind:

1. select the mobile nav-block-template and do our edits there
2. select preview mobile and adjust block

I haven't tried out style-injection with a FSE-theme yet. In my classic themes I have to workaround some style-injections that are not loaded inside the iframes of tablet/mobile-view. And I'm not sure, if this approach is the right one. Preview is for preview. However: when I think about it. This way, we could introduce a finer user-control for different screen-sizes.

[jordesign]

It seems this would be resolved by #43852