Improve links to "Navigation settings" pages

Thank @matthieuscarset! Good improvement adding the link on the Extend page :)

The problem is that that the resulting UI is confusing: it looks like the settings is a child of the Navigation blocks, and when you're on the Settings, it looks like the blocks is a child of the settings. So the resulting Information Architecture doesn't make sense with the current UI elements used ("perks" of using tabs everywhere!). I wonder if the title should be "Navigation" and the 2 of them below? I'm not sure about getting to deep with menus, but I can't think as a better solution right now.

It is confusing I agree.

I still think it is better to have "Settings" and "Blocks" grouped together to prevent the kind of "duplicated labels" under User Interface.

I suggest we place just one item under Admin > Config > UI > Navigation (see attached screenshot).

Note: I have updated the route and template links from `/navigation-block/...` to `/navigation/block/...` to keep consistency.

Moving to Needs work after getting Navigation into core.

This branch is still against the old 'navigation entity' which is now replaced with Layout API.

Closing this as duplicate as 🐛 Enhance Navigation admin workflow with Managed Tabs. Needs review is in review now

This is a surprise but okay.

🤷 This issue existed before the other. Why did we need to create a new one @SKAUGHT ?

Anyway, I will try to catch up on the changes on the other issue #3443556.

Thank you for linking the two.

We have come across a more specific problem on the new layout form (see details there) in a completely different light, and as the solution unfolded we then realized -- same solution! dups happen (:

cheers. I've added comment to add you for cred there as well.