[ANN] Clarabel.jl: New convex optimization solver

We will try to keep them as close as possible. Right now there are only minor design differences because there are some things that are possible or easy in one language but not the other.

In terms of overall numerical behaviour though, the two version are identical. I will make a Julia interface to the Rust version, and then we will be able to test both on a common set of test problems and compare outputs.