Merge origin/main into feat/document-file-conversion. Conflicts were
format-only (Tailwind class ordering, single-line vs multi-line) plus
two semantic merges:
- files.helpers.ts: combine main's pending-PDF download path with the
branch's original-source-file (DOCX/PNG/JPEG) download path
- download-pdf.ts: combine main's versionToFilenameSuffix helper with
the branch's server-provided Content-Disposition filename support
## Description
Replace the PDF renderer with an custom image renderer.
This allows us to remove the "react-pdf" dependency and allows us to use
a virtual list to improve performance.
This PR is handles the changes required to support envelopes. The new
envelope editor/signing page will be hidden during release.
The core changes here is to migrate the documents and templates model to
a centralized envelopes model.
Even though Documents and Templates are removed, from the user
perspective they will still exist as we remap envelopes to documents and
templates.