feat: Add ability to make proofs with an already computed proving key

[kevaundray]

resolves #1680

Checklist:

Remove the checklist to signal you've completed it. Enable auto-merge if the PR is ready to merge.

• If the pull request requires a cryptography review (e.g. cryptographic algorithm implementations) I have added the 'crypto' tag.
• I have reviewed my diff in github, line by line and removed unexpected formatting changes, testing logs, or commented-out code.
• Every change is related to the PR description.
• I have linked this pull request to relevant issues (if any exist).

[kevaundray]

There are a few things which are blocking this PR:

• The typescript main.js needs to be modified to accept the proving key path
• Should try and use writeKeys in tests, to see if performance is good enough to get rid of proveAndVerify
• Re-generate the exports.json file and barretenberg_api

For the last point, this seems to be broken due to bbmalloc retuning a void* return type, whereas the script expects only void return types for WASM_EXPORT. See here for the error which gets raised.

[kevaundray]

For the third point, #1683 has been opened

[kevaundray]

This is based off of #1672 , so once that gets merged, the diff will be smaller

[kevaundray]

@charlielye noted that the time it takes to copy a large proving key vs the time it takes to recompute it, can be about a difference of 2x.

Given that this does add complexity, going to close this for now until users complain about multiple proving times.

The issues regarding bindgen.sh not working will still need to be fixed regardless in separate PRs