refactor(AztecMacro): Make max note len error a compile time error

[rahul-kothari]

Ayush ran into the following error.

note_processor WARN Could not process note because of "Error: The note being processed has 27 fields, while "compute_note_hash_and_nullifier" can only handle a maximum of 20 fields. Please consider increasing the allowed field size to accommodate all notes generated from the contract.". Discarding note...

Comes from here

Can this error be a compile-time error? We have seemed to arrive 20 through this:

 maxNoteFields = (artifact.parameters[artifact.parameters.length - 1].type as ArrayType).length;

where artifact is the compute_note_hash_and_nullifier function artifact. Think we can extrapolate/reimplement in Noir and throw an error in the [#aztec(note)] macro

[LHerskind]

The value 20 was just because it needed a fixed size upper limit. We could likely crank it up to ensure it is not an issue for more cases, then not really needing the improved compile time error.

@nventuro had the intention of making the value be defined from the largest note in the contract, but as we were limited by the macros at that point we just used 20 as that value was already used somewhere else 🤷

[nventuro]

Yes, that's tracked on this issue. Recall this comment however:

Note that we're making the array be as large as MAX_NOTE_FIELDS_LENGTH (a limit on the return size of the view data oracle), so we're not really imposing any new constraints on note size by hardcoding the limit.

[Thunkar]

Closed in #5838