Cleanup: Remove Setup and Keccak (Setup) example

[oskarth]

It doesn't make much sense to do trusted setup in a mobile app, so we can remove this.

We also want to remove this API usage in other parts of the code.

[oskarth]

A bunch of this was removed from recent PR #75 by @vivianjeng

Maybe some left-overs for Setup, not sure?

[vivianjeng]

They are all replaced by proving with arkzkey and wasm
The issue can be closed. 🙏🏻

[oskarth]

This is a separate issue from OP now I realize, but we probably want to make this cleaner: https://github.com/oskarth/mopro/blob/main/mopro-ffi/src/lib.rs right now two generate_proof functions and it is a bit confusing which to use.

https://github.com/oskarth/mopro/blob/main/mopro-ffi/src/lib.rshttps://github.com/oskarth/mopro/blob/main/mopro-ffi/src/lib.rs 3 initialize functions, two generate proof, two verify proof and two interfaces :D

We'd want to simplify this a bit, and if there are options (like dylib, arkzkey, path etc) it should be clear. I believe this is also what @Meyanis95 referred to earlier in chat.

---

On OP issue we still have https://github.com/oskarth/mopro/blob/main/mopro-ios/MoproKit/Example/MoproKit/KeccakSetupViewController.swift with Setup in it. I think we should make this part more explicit, and maybe even remove some examples (?)