Support dylib

[oskarth]

Problem

Right now we use wasmer wasm for Circom witness generation and static lib for whole of mopro.

This might be a challenge in a few areas:

• Performance (dylib might be faster than interpreting wasm file for witness gen)
• Binary size (static lib quite big)
• Startup time
• Compliance with app store (for distribution, dylib might be better approach)

Notes

This might require some additional work regarding setup, library initialization etc.

Acceptance criteria

• Existing work cleaned up https://github.com/oskarth/mopro/pull/7
• dylib behavior hidden under a feature flag
• witness generation and proving integrated throughout
• basic numbers to compare witness gen and proof gen on real device
• updated docs on other ad hoc actions needed (install paths, code signing etc)