Most password managers used 100k until recently for the weaker sha256
version. We used 500k for the sha512 variant, so we should be good for a
while. Hopefully Matrix switches to argon2 or something better at that
point.

Signed-off-by: Vitaly Zaitsev <vitaly@easycoding.org>

It makes no sense for servers to send the parent object without events
and not sending an empty list, but strictly speaking that is spec
compliant, so...

Relates to https://github.com/Nheko-Reborn/nheko/issues/1257

* Add confetti support

fixes https://github.com/Nheko-Reborn/nheko/issues/1218