quick frontend(widget): added `with_duplicates` argument to getWidgets: when this argument is False, widgets with the same widget_hash are filtered to only return first one. It is True by default to keep former behaviour.

# 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()