Allow querying the gates in a Program in a single request to the backend.

[TomAFrench]

We've taken on some tech debt here as part of the folding epic as we need to pass a separate program to the backend for each function within a program.

noir/tooling/nargo_cli/src/cli/info_cmd.rs

Lines 281 to 306 in 4dfd7f0

	fn count_opcodes_and_gates_in_program(
	backend: &Backend,
	compiled_program: CompiledProgram,
	package: &Package,
	expression_width: ExpressionWidth,
	) -> Result<ProgramInfo, CliError> {
	let functions = compiled_program
	.program
	.functions
	.into_par_iter()
	.enumerate()
	.map(|(i, function)| -> Result<_, BackendError> {
	Ok(FunctionInfo {
	name: compiled_program.names[i].clone(),
	acir_opcodes: function.opcodes.len(),
	// Unconstrained functions do not matter to a backend circuit count so we pass nothing here
	circuit_size: backend.get_exact_circuit_size(&Program {
	functions: vec![function],
	unconstrained_functions: Vec::new(),
	})?,
	})
	})
	.collect::<Result<_, _>>()?;
	Ok(ProgramInfo { name: package.name.to_string(), expression_width, functions })
	}

[vezenovm]

Closing in favor of #4962

[TomAFrench]

I've opened AztecProtocol/aztec-packages#6168 to track the changes we need to make to bb. This is still something which we need to address.