Port MPT witness generator

[ChihChengLiang]

Description

MPT witness generator was developed here. We now port them to here.

Issue Link

#1566

Type of change

New feature (non-breaking change which adds functionality)

Contents

• All repo contents from https://github.com/privacy-scaling-explorations/mpt-witness-generator

Rationale

• We port the raw repo content here. No modification except removing .git folder. This way, we don't hide any modifications in the big diffs.
• We expect further changes in the following PR

How Has This Been Tested?

No test

[ChihChengLiang]

This CI does nothing in this repo yet. Will fix them in the following PRs.

[ed255]

LGTM following the rationale described in the PR (which is just moving the external repo to zkevm-circuits, and iterate the implementation in future PRs)

From the quick look here are some comments that could be addressed in future PRs:

1. Make it explicit which files come from go-ethereum and which ones are new. Also mention the go-ethereum version used (or the commit hash). For the files that come from go-ethereum, make it explicit which functions/types have been changed or introduced.
2. I noticed lines of commented code. I think some of that comes from go-ethereum file; maybe the desire was to disable some functionality. Comments on why that is disabled would be helpful
3. In some of the test files I noticed many functions that look very similar but have different input-ouputs. I think there's a big opportunity of reusing code there.
4. Are all the files and functions strictly needed? For types and public functions that are not modified, could we instead import them from go-ethereum instead of copying them?

Regarding possible formatting of the code in future PRs, I think it would be ideal if the files imported from go-ethereum are not formatted differently than they appear in go-ethereum, so we can quickly diff both sides to see the differences without noise.

[adria0]

LGTM for dropping the go code into the repo.

Note that I will be working on the rust wrapper because I need it for the light client.
Follow https://github.com/privacy-scaling-explorations/zkevm-circuits/tree/zklight for the changes.