Customize: Prevent infinite full refresh from occurring when selective refresh...

Customize: Prevent infinite full refresh from occurring when selective refresh falls back for a nav menu that has items excluded from rendering via filtering.

See #37032.
Fixes #38612.

Built from https://develop.svn.wordpress.org/trunk@39510


git-svn-id: https://core.svn.wordpress.org/trunk@39450 1a063a9b-81f0-0310-95a4-ce76da25c4cd