fix: error on missing function parameters

[asterite]

Description

Problem

Resolves #6960

Summary

It turns out fn main { } was parsed without producing an error. This PR adds that error with messages similar to Rust. With that error, nargo fmt now correctly refuses to format the file.

Additional Context

Documentation

Check one:

• No documentation needed.
• Documentation included in this PR.
• [For Experimental Features] Documentation to be submitted in a separate PR.

PR Checklist

• I have tested the changes locally.
• I have formatted the changes with Prettier and/or cargo fmt on default settings.

[github-actions]

Compilation Report

Program	Compilation Time	%
sha256_regression	1.312s	-1%
regression_4709	0.774s	0%
ram_blowup_regression	14.820s	0%
rollup-root	3.580s	5%
rollup-block-merge	4.660s	35%
rollup-base-public	28.900s	-1%
rollup-base-private	12.400s	-7%
private-kernel-tail	1.032s	-5%
private-kernel-reset	6.522s	-5%
private-kernel-inner	2.184s	4%
noir-contracts	83.500s	-2%

[github-actions]

Execution Report

Program	Execution Time	%
sha256_regression	0.099s	-2%
regression_4709	0.001s	0%
ram_blowup_regression	0.579s	0%
rollup-root	0.105s	0%
rollup-block-merge	0.106s	0%
rollup-base-public	1.440s	1%
rollup-base-private	0.642s	-2%
private-kernel-tail	0.023s	0%
private-kernel-reset	0.386s	-1%
private-kernel-inner	0.116s	0%

[github-actions]

Execution Memory Report

Program	Peak Memory
keccak256	74.61M
workspace	123.78M
regression_4709	315.93M
ram_blowup_regression	512.47M
rollup-base-public	773.36M
rollup-base-private	424.92M
private-kernel-tail	182.01M
private-kernel-reset	255.59M
private-kernel-inner	215.19M

[github-actions]

Compilation Memory Report

Program	Peak Memory
keccak256	78.50M
workspace	123.71M
regression_4709	422.91M
ram_blowup_regression	1.58G
rollup-base-public	2.55G
rollup-base-private	1.25G
private-kernel-tail	201.97M
private-kernel-reset	716.60M
private-kernel-inner	292.24M