Navigation block: Submenu block settings should be discoverable from the Submenu block itself

[rohitmathur-7]

What?

Closes #75977

Why?

The settings for the Submenu block should be visible in the Submenu block only and not Navigation block.

How?

Moved the Submenu block settings from Navigation block to the Submenu block.

Testing Instructions

• Open a page.
• Add a Navigation block.
• Create Submenu inside of it.
• Check the Submenu block settings now, Submenu Visibility and Show Arrow settings is now visible.
• Check the Navigation block settings, Submenu related setting has been removed from there.

Screenshots or screencast

[github-actions]

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