Move toctoggle from mediawiki.util.js to separate file mediawiki.toc.js

* New file mediawiki.toc.js without global function.
* Keep minimal function mediaWiki.util.toggleToc() for compatibility.
* Mark mediaWiki.util.toggleToc() as deprecated.
* Adapt mediawiki.util.test.js.
* Add new file mediawiki.toc.test.js.
* Solves bug 60030 and allow multiple toc.

Bug: 60030
Change-Id: I3ca2acb70db98d00e3f1bd2227091bd32d8e18a5
Merge "Move toctoggle from mediawiki.util.js to separate file mediawiki.toc.js"