Add a new url parameter for disabling warnings in the case of possible data loss

[aki2014]

Steps to reproduce the problem:

1. Because of the following enhancement:
   Notify the user about form data loss when another document is opened #12257
   when leaving a page, we see a waning. But in some cases we don't want to show warnings to users.

I would like to request you to add a new url parameter for disable warning in the case of possible data loss.

2. The blow is not my post but the same issue as I described here.
   https://stackoverflow.com/questions/74865020/remove-warning-when-navigating-away-from-changed-form-in-pdf-js-viewer

[Snuffleupagus]

Please note that controlling API- and/or viewer-features using hash parameters was purposely disabled, see issue #4954 for additional information, hence we will unfortunately not be adding any new ones to customize/configure the default viewer.

Also, please see http://mozilla.github.io/pdf.js/getting_started/#introduction (emphasis mine):

The viewer is built on the display layer and is the UI for PDF viewer in Firefox and the other browser extensions within the project. It can be a good starting point for building your own viewer. However, we do ask if you plan to embed the viewer in your own site, that it not just be an unmodified version. Please re-skin it or build upon it.