Provide message/warning/error box abstraction

Provide message/warning/error box abstraction

This will help us consolidate the various uses into one single
method which will help us drive standardisation of these defacto
widgets.

Hopefully, by being a method of the Html class, which has a very
low barrier for use will drive down the inconsistent display of
warning/error boxes across MediaWiki's products

Various usages of warningbox and errorbox have been ported over.
I've retained some more complicated usages which make use of the
parser (wrapWikiMsg) and any where id and class are medled with
- we'll probably want to consider whether we want to encourage
those going forward as they encourage adjusting the styling.

Bug: T166915
Change-Id: I2757e1f4ff2599e93a7257fc644cab69063896d2