Fix#850 (marked stale many years ago, but now reopened). User had a typo in their script which would have caused problems no matter what. However, it exposed another problem. Style Alignment Read Order was supported only by the Xlsx Reader and Writer, but it could have been supported pretty easily for most other formats. This PR adds support for the following:
- Xls (read and write)
- Html (write, and read using inline styles). Html reader does not yet process most classes.
- Pdf (write). PhpSpreadsheet does not have a Pdf reader.
- Ods (write). PhpSpreadsheet does not yet support reading most Ods styles.
- Xml (read). PhpSpreadsheet does not have an Xml writer.
- Gnumeric (no change). It appears that the Gnumeric product does not support this attribute.
- Csv (no change). Csv does not support any styles.
- Slk (no change). Slk does not support non-Latin characters, so this attribute doesn't make sense for it.