add alternative handling

create wesnoth-tools package containing:
 - byte-compile .py modules?

make package lintian clean

replace addon manager JS ECCs with libjs-jquery and libjs-jquery-tablesorter
 - upstream commit 81c31c40c53 (2023-08-05) updated these for the first time
   since commit 72111578453 (2008-10-12) with no compatibility issues, so it
   seems unlikely that further updates in Debian will break anything

data/tools/wesnoth_addon_manager uses data/tools/addon_manager/html.py (all in
wesnoth-BRANCH-tools) to generate a local HTML file that loads remote resources
(hidden from lintian's files/privacy-breach check, which should generate a
privacy-breach-generic warning but doesn't):
 - https://fonts.googleapis.com/css?family=Montaga%7COpen+Sans:400,400i,700,700i
   fonts-open-sans is in Debian but Montaga (SIL OFL) isn't, so package or put
   in debian/, and write CSS
 - https://www.wesnoth.org/wesmere/img/favicon-32.png
   can be put in debian/
 - https://www.wesnoth.org/wesmere/img/favicon-16.png
   same
 - https://www.wesnoth.org/wesmere/css/wesmere-1.1.1.css
   complicated, built from https://github.com/wesnoth/wesmere sources (which may
   need wesmere/sass/nonfree/_assets.scss removed for Debian) using Dart Sass
   (can port wesmere/Makefile to use sassc in Debian) and zopfli (in Debian)
 - https://www.wesnoth.org/wesmere/js/modernizr.js
   see above about JS ECCs, use libjs-modernizr
could patch out HTML generation altogether, also solving JS ECCs
current workaround: patch in a privacy breach warning

data/tools/wesnoth_addon_manager removed with 1:1.18.0-1 but keeping the notes
above intact in case we decide to ship the standalone client again for some
reason. Also, https://lists.debian.org/debian-devel-games/2024/02/msg00006.html
