RTL is now properly handled in these cases:
- `dir: rtl` (or `ltr`) in document metadata
- an RTL `lang` in metadata (e.g. `he`, `ar`), unless overridden
by `dir`
- a `dir` attribute on a Div
The OpenDocument writer tracks the active writing mode and, when it
is RTL, emits automatic paragraph styles with
`style:writing-mode="rl-tb"` derived from the usual named styles
(deduplicated per parent style). `fo:text-align` is also used
to get the matching text alignment.
Code blocks remain ltr regardless.
Closes#11301.
With some help from Claude Fable.
John MacFarlane
7b866613f6