Fix the admin toolbar js when jQuery is not present and replace the jQuery...

Fix the admin toolbar js when jQuery is not present and replace the jQuery based hoverIntent.js with a native implementation. Introduces the "hoverintent" (no dependencies) package.

Props dinhtungdu, audrasjb, azaozz.
Fixes #47069.
Built from https://develop.svn.wordpress.org/trunk@46872


git-svn-id: https://core.svn.wordpress.org/trunk@46672 1a063a9b-81f0-0310-95a4-ce76da25c4cd