investigate non-deterministic serialized pk/vk

[hero78119]

To reproduces:

1. cargo ceno keygen --out-vk vk.bin
2. cargo ceno keygen --out-vk vk2.bin

=> vk.bin & vk2.bin are a bit different on the file size

background

It was found from #1054

• serialized more meta info into vk to carry over information from keygen
  -> e.g. field = babybear/goldilocks, public io size, ...
• skip pk/vk generation in prove phase
• fixed expression serialization to be canonical