While Serai only needs the simple DLEq which was already present under
monero, this migrates the implementation of the cross-group DLEq I
maintain into Serai. This was to have full access to the ecosystem of
libraries built under Serai while also ensuring support for it.
The cross_group curve, which is extremely experimental, is feature
flagged off. So is the built in serialization functionality, as this
should be possible to make nostd once const generics are full featured,
yet the implemented serialization adds the additional barrier of
std::io.
Combines the existing frost-rs, dalek-ff-group, and monero-rs repos into
a monorepo. Makes tweaks necessary as needed. Replaces RedDSA (which was
going to be stubbed out into a new folder for now) with an offset system
that voids its need and allows stealth addresses with CLSAG.
