Rename maybe_regenerate_attachment_metadata() to wp_maybe_generate_attachment_metadata(), to match wp_generate_attachment_metadata().

fixes #26825.

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git-svn-id: http://core.svn.wordpress.org/trunk@27245 1a063a9b-81f0-0310-95a4-ce76da25c4cd
Update the Customizer API inline docs.

props ericlewis.
fixes #27065.

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git-svn-id: http://core.svn.wordpress.org/trunk@27246 1a063a9b-81f0-0310-95a4-ce76da25c4cd