Add 64-bit version to all instructions

[quangvdao]

This PR makes all current Jolt instructions have a 32-bit and a 64-bit version.

Importantly, it does not change the behavior of 32-bit instructions, nor change the list of subtables.

List of changes:

• Parametrize all instructions by word size
  • This is necessary so that the random() function correctly returns random u64s for 64-bit word sizes
• Add instruction behavior for 64-bit word size (or document that the behavior does not change for 64-bit word size)
• Add test cases for 64-bit word sizes (all tests passed)
• Add more detailed documentation to all instruction_utils functions

[moodlezoup]

beautiful, just a couple of questions

[quangvdao]

One final note for this PR: currently, I don't know how the rest of Jolt uses the range-checking part of the store operations. I'll keep this in mind as I work to integrate 64-bit instructions for the rest of Jolt, just to make sure there's no under-constrained part (esp. with regards to range-checking store values). The 32-bit version is fine since it's still identical to before.