Filter module: Add a data-path-id for internal links to make it easier to track and update internal paths

Description of the need

This is a follow-up to https://github.com/backdrop/backdrop-issues/issues/4630. The idea is to be able to more easily track and update internal paths if they appear in text that's passing through filters.

Proposed solution

Make it work like the file upload, which produces something like:

<p><a data-file-id="7" href="/files/inline-files/document.pdf">document</a></p>

In this case the ID would have to be the pid in url_alias table.

Alternatives that have been considered

Maybe it's possible for the filter dialog to strip the leading slash and possibly decode the path to find a possible match. But that's more difficult than just looking for the alias via the pid.