If data-mw.body.html is not set, search for the element
whose ID matches data-mw.body.id and use its contents.
.body.html is still used for new content: new references
use .body.html, and if a reference using .body.id is
changed, the changed HTML is output in .body.html.
Bug: T88650
Change-Id: I5d614927256d59a3ab20b0bd6e882b5cb8fcda20
New changes:
a047e72 [BREAKING CHANGE] Create ve.dm.Focusable and store focusable flag there
Local changes:
* Add new ve.dm.FocusableNode mixin where required
Change-Id: Ie9ee2de05acfe3c4c62c4864e65bd20397d6a069