Use a proper docs-specific variable for the first parameter passed to the `embed_oembed_discover` filter.

See #26869.

Built from https://develop.svn.wordpress.org/trunk@28378


git-svn-id: http://core.svn.wordpress.org/trunk@28206 1a063a9b-81f0-0310-95a4-ce76da25c4cd
Eliminate use of `extract()` in `wp_get_archives()`. 

Adds unit tests: `tests/functions/getArchives.php`. 
All other unit tests pass.

Props MikeHansenMe, wonderboymusic.
See #22400.

Built from https://develop.svn.wordpress.org/trunk@28379


git-svn-id: http://core.svn.wordpress.org/trunk@28207 1a063a9b-81f0-0310-95a4-ce76da25c4cd