fix: Reject invalid expression with in CLI parser

[aakoshh]

Description

Problem*

Resolves #5560

Summary*

Rejects an invalid --expression-value in the CLI, which would later cause a panic in acvm::compiler::transformers::csat.

An example error message looks like:

error: invalid value '1' for '--expression-width <EXPRESSION_WIDTH>': minimum value is 3

Additional Context

The issue suggests that CSatTransformer::new should return a Result explaining the problem it has with width, rather than doing an assert! (without any message) and crashing the program. I agree, however looking at the chain of calls, none of the half-dozen functions we go through to reach this use Result, and the CSatTransformer is the only option we have. This suggests to me that this limitation is perhaps supposed to be well-known to the user, ie. it's not the case that one transformer has X limit and another has Y limit.

For this reason I added a pub const MIN_EXPRESSION_WIDTH: usize = 3; to the acvm::compiler module and using that as a common value for the assertion as well as the validation in the CLI. Should the assumption of a single global value change, removing that will force us to update the validation logic as well.

That said if you prefer going the Result route I'm not against it, it just seemed like an overkill for this single use case.

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.

[TomAFrench]

LGTM pending removal of changes which break benchmarks.