refactor Paths and update build workflow

+ rename app_dir -> config_dir and config_dir to config_parent
+ bundle web client as zip
+ bundle and extract client zip when running pyinstaller builds
+ installer pyinstaller as main dependency
+ remove fallback client flag
+ handle already used port
+ add assethandler class
+ remove some startup logs
+ ignore wheels and client.zip files

appimage/entrypoint.sh

@@ -1 +1 @@
-exec "${APPDIR}/usr/bin/python" -m swingmusic --fallback-client "${APPDIR}/client" "$@"
+exec "${APPDIR}/usr/bin/python" -m swingmusic --client "${APPDIR}/client" "$@"