Add blanket support for mediawiki ui via globals

This provides better mobile experiences on various pages
and a more consistent UI across both mobile and desktop.

It does this in two ways.

1) Forces HTMLForms to not use table based layouts so as
not to interfere with responsive nature of mediawiki ui elements

2) Applies MediaWiki.UI classes to most pages
If a page is created via Xml or Html classes it will use mediawiki ui
Where possible I've added classes unconditionally, but for cases of buttons
this is behind the $wgUseMediaWikiUIEverywhere global since button styling is
enabled on pages by default and for checkboxes since it is changes HTML markup.

3) Adds all MediaWiki.UI styles to pages which can use it
When enabled:
* Apply these styles to all pages which use HTMLForms
* Apply to EditPage
* Apply to anything that uses certain elements outputted by the
Xml or HTML helper classes
* Apply to History page
* Apply to protection page
* Apply to move page
* Apply to deletion page

Currently kept behind a global to allow us time to finetune
existing elements. After further testing we will look to kill the
globals and make mediawiki.ui the default

See: I430c0fbb79d2a33bb828b2427bda0ee01115d73f
Change-Id: I47db5eab4569514d039261d11b6dedb0eeae17b5
Merge "Add blanket support for mediawiki ui via globals"