NEXTPY-569 -- Make pdfquery compatible with Python 3.9 and 3.11

[kdleijer]

Update documentation, formatting, some imports.
That's it :-)

[jopispnext]

✅
Checked for potential security issues
Checked for code optimization
Checked for code duplication
Checked for whether names are descriptive enough
Checked for possible performance improvements
Checked for the presence and quality of tests
Checked for additional code documentation