Navigation: Add border and spacing support

[rinkalpagdar]

What?

Add border block support to the navigation block.
Part of #43247
Part of #43243

Why?

The Navigation block is missing border support.

How?

Adds the border block support in block.json

Testing Instructions

1. Go to the Global Styles setting ( under appearance > editor > styles > edit styles > blocks )
2. Make sure that the navigation block's border is configurable via Global Styles
3. Verify that Global Styles are applied correctly in the editor and frontend
4. Edit the template/page, Add a Navigation block and Apply the border styles
5. Verify that block styles take precedence over global styles
6. Verify that block borders display correctly in both the editor and frontend

Note

Please confirm that we need a border for items and a wrapper for navigation as shown in the frontend image below.

Screenshots or screencast

FrontEnd:

Backend:

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