Each change is tested manually line by line. There are too many changes
so I can't share dozens of screenshots.
In short:
1. `ui right` could be still used in `ui top attached header`, because
there is a special case.
2. A lot of `ui right` are just no-op, so they can be removed safely.
3. Some of the `ui right` should be replaced by `gt-float-right` (to
avoid breaking, leave them to the future).
4. A few of the `ui right` could be rewritten by flex.