chore: Implement FromStr and Into<String> for CrateName

[phated]

Description

Problem*

Resolves #2060

Summary*

This implements proper traits for CrateName instead of relying on an ad-hoc API. Implementing FromStr allows us to use .parse() on a &str to get a CrateName, and it allows us to use CrateName as a type with clap derivers (or any other APIs that use .parse().

This work fell out of #1992 but should be merged as a prerequisite.

Documentation

• This PR requires documentation updates when merged.

  • I will submit a noir-lang/docs PR.
  • I will request for and support Dev Rel's help in documenting this PR.

Additional Context

PR Checklist*

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