tools (common/template): theme settings with possibility to disable default fallback for CSS: - themes can now have a `settings.json` file at their root to modify the renderer behaviour - the `css_default_fallback` boolean (true by default) can be used to disable the fallback mechanism when CSS files are checked. Useful when a theme doesn't follow the CSS naming of default theme. - introduced some type hints

# XXX: the Monkey Patch is here and not in src/__init__ to avoir issues with pyjamas compilation
# TODO: remove this when changes are merged in Wokkel
from sat_tmp.wokkel import install
install()