Backport libvmg's implementation into the main core

[ShinySaana]

Not sure if you would want to merge this (as-is or with changes), but we thought we might as well create the PR in case that's of interest to you !

[jotego]

I would prefer if the filter stuff is left out of this repository because as it is now, it is a good reference for the original circuit logic. So functionality outside of the scope of the original digital logic is better kept outside. That's just my personal preference.