Support editing already existing ink-/stamp-annotations

[DDHSchmidt]

Disclaimer: This is more or less a clone of issue #15403 with an expanded scope

Attach (recommended) or Link to PDF file here: dummy.pdf

Configuration:

• Web browser and its version: Firefox 116.0.3
• Operating system and its version: Windows 10 (22H2)
• PDF.js version: 3.8.110
• Is a browser extension: No

Steps to reproduce the problem:

1. Add an ink or stamp annotation
2. Save the pdf under a different name
3. Reload the saved pdf
4. The added ink-/stamp-annotations are "burnt in" and can't be edited anymore

What is the expected behavior? (add screenshot) I would have expected to be able to edit/remove the added annotations.

What went wrong? (add screenshot) The annotations are "burnt in" after saving. Subsequent reloads of the pdf won't let me edit or remove them

[atrinker]

Are there any plans to move on this issue in an upcoming release?

[marco-c]

Yes, we are planning to work on this soon. However, if you're up for it, we'd happily accept contributions to make it happen faster.