fix: sort embedded file name tree entries

[Guflly]

What?

Keeps EmbeddedFiles name-tree keys sorted by their encoded PDF bytes.

Why?

Acrobat rejects some attachments when names such as 1.jpg, 2.jpg, and 10.jpg are stored out of order.

How?

The attachment key and reference are inserted at the correct byte-sorted position in the name tree.

Testing?

Ran the full unit suite (804 passed, 1 skipped), typecheck, ESLint, Prettier, and the full build. A targeted Node check and real Chrome and Firefox browser checks verified byte-sorted attachment names in both a newly created PDF and an existing fixture. Chrome's PDF viewer rendered both generated documents. Deno and the complete desktop viewer matrix were not run.

New Dependencies?

No.

Screenshots

N/A.

Suggested Reading?

No.

Anything Else?

Closes #89.

Checklist

• I read CONTRIBUTING.md.
• I read MAINTAINERSHIP.md#pull-requests.
• I added/updated unit tests for my changes.
• I added/updated integration tests for my changes.
• I ran the integration tests.
• I tested my changes in Node, Deno, and the browser.
• I viewed documents produced with my changes in Adobe Acrobat, Foxit Reader, Firefox, and Chrome.
• I added/updated doc comments for any new/modified public APIs.
• My changes work for both new and existing PDF files.
• I ran the linter on my changes.

[Sharcoux]

Thanks for the PR. You're right about the problem. But I fixed with a commit that also handles the problem with js scripts. Can you test with version 2.8.2 please?