Fix#1104, which went stale over 6 years ago, and is now reopened. This PR addresses the alignment of the table, not alignment of text. Support is added for the following:
- Html. Full support.
- Mpdf. Full support, except that, when mixed LTR and RTL worksheets are output, all tables will be on the left of the page (but will be properly aligned).
- Tcpdf. Full support when all worksheets being output are RTL; no support when mixed LTR and RTL worksheets are output.
- Dompdf. No support.