* Leverage the infrastructure around feature management to handle the page tools
pinning and persistence
* Make pinnableHeader.js leverage features.js if the data-feature-name attribute
is set
* Sets tests/.eslintrc.json ecmaVersion to 2018 to enable destructuring in test
files.
* Adds a isPinned helper method to pinnableElement
* Add a logged in requirement so that the pinned feature is disabled for
anon users.
Bug: T322051
Change-Id: Ib86282216882fa94e37b7088a3f4bd0c1bcf6cd4
