Noir contract cleanup and small fixes.

[LeilaWang]

Description

• Do not assume the order of new commitments will be the same as logs => Compare all note hashes to find its nonce.
• The read request is always correct but the nullifier could be created with the wrong value => Check the return notes from oracle have the correct contract address and storage slot.
• Rename Set.has to Set.assert_contains.
• Automatically nullify and create new note in Singleton.getNote.
• Hash with index INITIALISATION_NULLIFIER.

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.