add proof-generation crate for masp integration

[semaraugusto]

Summary of changes

• Adds MaspDelegatedProver for generating proof in behalf of the user
• Adds MaspBatchProver for generating merkle tree batch insertion proofs (works for depositTree, UnspentTree and SpentTree bc the prover doesn't depend on the merkle-tree itself)
• Adds tests for both provers by providing pre-generated proof inputs

Batch Prover spec https://www.notion.so/hicommonwealth/Batched-deposit-processing-8a9cbea47acc448cb1076fac86161fd0

Delegated prover spec https://www.notion.so/hicommonwealth/Delegatable-proof-generation-c8d64aa16957407496e5c706130346d7

Reference issue to close (if applicable)

• Closes https://github.com/webb-tools/relayer/issues/441

• Closes https://github.com/webb-tools/relayer/issues/433

• Closes https://github.com/webb-tools/relayer/issues/437

  Code Checklist

• [ ] Tested

• [ ] Documented

[shekohex]

It would be good to have a meeting or a call about this PR and the overall task so I could understand better and review the PR with the correct assumptions.

[shekohex]

And ofc we need to clean up and fix the tests.