feat(accounts): Store signing public keys in immutable private notes in account contracts

[spalladino]

• Properly stores and loads the public key from an ImmutableSingleton in an ecdsa account contract.
• More fixes to e2e account test.
• Add new debug call in Noir to log an array with a string prefix (so we know what we're logging since they print out of order)
• Rollback Using bb ECDSA #954 since barretenberg ECDSA doesn't verify in Noir.
• Reenable tests for ECDSA account contract.
• Rename current Schnorr account to SchnorrSingleKey.
• Introduce new SchnorrMultiKey account contract that stores its signing key as a private note following the same approach as the refactored ECDSA account contract.

Fixes #1007

[spalladino]

@LeilaWang should this be part of ImmutableSingleton#initialise? Or is there a scenario where we may want to initialise it without emitting the corresponding encrypted log?

[LeilaWang]

I actually thought about the same - emitting a log when a note is created (in singleton.initialise, set.insert, etc). But then decided to keep it separate. Because in some use cases we might want to emit unencrypted logs instead of encrypted ones. And in some use cases, like you said, we might not want to emit anything at all (for example, the ClaimNote in zk_token_contract).

[LeilaWang]

I've added a header to a note in a recent PR, and will change the emit apis to be cleaner since we won't be passing context, contract address and storage slot around :)

[benesjan]

Just minor issues. Happy to approve once addressed.

[LeilaWang]

I actually thought about the same - emitting a log when a note is created (in singleton.initialise, set.insert, etc). But then decided to keep it separate. Because in some use cases we might want to emit unencrypted logs instead of encrypted ones. And in some use cases, like you said, we might not want to emit anything at all (for example, the ClaimNote in zk_token_contract).

[LeilaWang]

I've added a header to a note in a recent PR, and will change the emit apis to be cleaner since we won't be passing context, contract address and storage slot around :)