Docs: Add and correct `@since` docs for a variety of functions and methods.

Props keesiemeijer, chris_dev
Fixes #39343, #39357, #39344
See #39130

Built from https://develop.svn.wordpress.org/trunk@39638


git-svn-id: https://core.svn.wordpress.org/trunk@39578 1a063a9b-81f0-0310-95a4-ce76da25c4cd