Consolidate collapse table CSS and JavaScript

Authored by Niedzielski on Apr 21 2017, 2:40 AM.

Description

Consolidate collapse table CSS and JavaScript

Move collapse table to wikimedia-page-library.

https://github.com/wikimedia/wikimedia-page-library/pull/3
https://gerrit.wikimedia.org/r/#/c/349371/

Change-Id: I0e104eb74661daddbaf101bd4164ccce55ab9b5f
Depends-On: Ie1848e5543e7ae51431671ad0db189c1e9a42874
Bug: T158309