Add intra-app pill link action to matrix.to links

Background

It is useful and common to share matrix.to permalinks to people outside Matrix by showing matrix.to links that I can right-click to copy the URL for them.

However, as a user viewing something in the Matrix Public Archive, I can't navigate such permalinks within the Matrix Public Archive site and have to manually resolve the matrix.to link to the archive URL pattern.

(or have http-links disabled, etc)

Potential solution

Please add an onclick handler that opens the respective screen and/or scrolls to the referenced message or an equivalent fallback without JavaScript (e.g., either always rewrite such URL to point within the archive or perhaps include the original link in parenthesis).

This affects at least user submitted matrix.to links, room and user pills and generated references to the message and the user hidden behind the In reply to header.

Related: #235 https://github.com/vector-im/hydrogen-web/issues/1104

Start by tracing how the archive renders user-submitted matrix.to links, room and user pills, generated message references, and the In reply to header. Determine how each link can resolve within the archive and what non-JavaScript fallback is supported; done means these references open or navigate to the corresponding archive content without manual URL conversion.