Rearrange noir files.

[LeilaWang]

Description

• Rename token-utils to value-note.
• Move noir-aztec and value-note to noir-libs.
• Move claim-note and transparent-note to the contracts that use them.
• Rename examples to artifacts.

Checklist:

• I have reviewed my diff in github, line by line.
• Every change is related to the PR description.
• I have linked this pull request to the issue(s) that it resolves.
• There are no unexpected formatting changes, superfluous debug logs, or commented-out code.
• The branch has been merged or rebased against the head of its merge target.
• I'm happy for the PR to be merged at the reviewer's next convenience.

[iAmMichaelConnor]

Very nice!

I wonder if the following additional changes would be good:

• Move value_note into noir-libs/noir-aztec/notes/ because it's a note which will only really be used in the context of aztec? (Or maybe move it into custom-notes?
• Rename noir-aztec to aztec. Remove noir-aztec and move all its contents up a level to noir-libs/
• Rename noir-libs to lib?
• Rename src/contracts to src/examples because these are example contracts?

Thoughts?

[LeilaWang]

Move value_note into noir-libs/noir-aztec/notes/ because it's a note which will only really be used in the context of aztec? (Or maybe move it into custom-notes?

Think it's cleaner to make value_note a separate library/crate. Because it's just one type of note people can use in aztec. They can choose not to use it and instead use other published crates for similar or different purpose.

Rename src/contracts to src/examples because these are example contracts?

I still prefer src/contracts XD They are the real contract files in the noir-contracts package. Alongside are types and artefacts. But maybe we can rename noir-contracts to noir-example-contracts if we want to be clear they are just examples?

Rename noir-aztec to aztec. Remove noir-aztec and move all its contents up a level to noir-libs/
Rename noir-libs to lib?

Right now they still live in yarn-packages, so it might look unclear if it's just lib:

├-- yarn-packages
│   ├-- noir-contracts/src
│   │  ├-- contracts
│   │  ├-- artefacts
│   │  ├-- types
│   ├-- lib

But eventually, we can probably move them to its own workspace and flatten the structure:

├-- yarn-packages
├-- noir-packages
│   ├-- aztec
│   ├-- value-note
│   ├-- zk_token_example_contract