Update www/cutelyst to latest upstream release, 2.10.0

Release announcement is at
https://dantti.wordpress.com/2020/02/17/cutelyst-2-10-0-and-simplemail-v2-released/
It just says "many important bugfixes", though. No details.

While here, I've enabled two plugins in cutelyst, CSRF protection
and static compression support. This isn't at the BUILD_ALL level,
but should make cutelyst more useful in its default package state.