=== What works:
Exporting text and media files of the currently visible conversation to
a zip file containing an HTML file with the text, including links to the
media files, as well as the media files. The Signal Desktop CSS file is
included to achieve the same styling as in the app (but without any
controls, which do not make sense in a static settings).
=== What does not work:
It does not yet load all messages back to the beginning of history.
The fonts are not included in the zip file, for even more proper
The conversation avatar (if present) is not included.
The code is far from being in good shape.
=== Note to reviewers
I know that the code is not a shape to be merged, but it works for me.
I am interested in cleaning it up to be mergable if the general
functionaliy is desired (i.e. I will not fix code cosmetics if in the
end the pull request is reject because the feature is not wanted.)