Is your feature request related to a problem? Please describe.
This was supposedly raised and addressed as part of #1354

But I can't seem to get any metadata regarding the inferred heading of any content I test with.

All Title elements all have the same level at the moment which isn't an accurate representation of the parsed document.

Describe the solution you'd like
The parser should be able to infer PDF hierarchy in a couple ways:

• Through the document outline, e.g. example PDF linked on https://pdfa.org/techniques-for-accessible-pdf/headings-with-different-levels-correctly-tagged/UA1_Tpdf-H_03/
• Calculate and infer the heading size relative to the size of the page (and other headings within the same page/document).

Describe alternatives you've considered
N/A

Additional context