OO.ui.BookletLayout does not respect tabindices when trying to focus
the first focusable element after a page is switched. Remove the need
for manually set tabindices in ve.ui.MWTemplateDialog by using natural
DOM order and absolutely positioning things to keep current design.
Bug: T114562
Change-Id: I7a18a455f9fa80eb3d2ea17bff8139e0194c0fbf