This converts the public `uiLayoutAbsolute ` and `uiLayoutAbsoluteBlock` functions to an object oriented API (an `uiLayout::absolute` and `uiLayout::absolute_block` respectively), following recent changes. `uiLayout::absolute` now returns an uiLayout reference instead of a pointer. New calls to this method should use references too. Part of: #117604 Pull Request: https://projects.blender.org/blender/blender/pulls/138546