More effective wings disk quota enforcement

[iamkubi]

Currently disk quota enforcement only happens on a set interval, and it's way too long (I believe necessarily for performance reasons). We should improve the way quota is enforced to prevent attacks that exploit this enforcement interval to consume more disk than allowed.

A previous attempt had been made to implement virtual disks, but that didn't end up getting implemented, not sure why. The existing UFS filesystem appears to implement quotas, not sure if those work, but presumably not given the wings disk enforcement is still present.

Further investigation needed to figure out what exists and what a good path forward would be.