Customizer menu live preview not updating when adding and removing menu items

[stuartshields]

When using the Customizer menu and adding items to a menu after "Save & Publish" is hit, the live "preview" doesn't update to show the newly updated menu items. The page needs to be refreshed for the new items to show.

[netweb]

The original reporter is running Beta 3 (r33288), my test below is using r33291

In the following video it shows similar to the reported issue, though in this case I'm removing an item from the menu and live preview does not update, the menu item does not show it has been removed until after closing the customizer:

​https://cloudup.com/cMJPCfudufe

[westonruter]

​https://github.com/xwp/wordpress-develop/pull/103

[westonruter]

@stuartshields, @netweb: I believe I've addressed the issues identified in 33010.diff​. Please test.

I believe the main issue was introduced with the performance optimizations done in [33138], so part of the fix is to ensure that all of the relevant settings get sent along with the partial-refresh request for the menu, including any deleted menu items and any settings for nav menu locations. I also noticed a conflict with the Customizer Partial Refresh plugin which I hadn't noticed before, so I made the binding of the setting change events more robust as well.

[stuartshields]

@westonruter I've tested it and it works. Thanks for the fix.

[netweb]

Likewise for me, works as expected now, thanks Weston.

[westonruter]

In 33328:

Customizer: Fix previewing certain changes to nav menus.

Addresses regression introduced in [33138], where deleted menu items would not be removed from the preview, and changes to a location's assigned menu would likewise not preview. Also makes the binding of the setting change events more robust.

Fixes #33010.