Wrong text direction in ToC for RTL languages in PDF export

[seluianova]

Describe the Bug

ToC has wrong text direction for right-to-left languages in PDF export

Steps to Reproduce

1. Go to 'Pages'
2. Select any right-to-left language, for example Arabic
3. Select any parent page containing child pages, for example "German language"
4. Select bulk action --> Export as PDF
5. Check Table of Content in the exported PDF

Expected Behavior

Table of Content has right-to-left text direction (as well as pages themselves)

Actual Behavior

Table of Content has left-to-right text direction

Additional Information

ToC is generated by xhtml2pdf
<div dir="rtl">
<pdf:toc/>
</div>

The issue should be probably fixed on their side:
xhtml2pdf/xhtml2pdf#664

Within this task we can update the library version and our tests as soon as the issue is fixed.