feat: Allow globals to refer to any expression

[jfecher]

Description

Problem*

Resolves #1734

Summary*

Allows globals to be defined as any expression using the dependency graph to ensure there are no cycles.

Note that globals defined via a function call are allowed: global FOO = bar();, although the function will be
re-called each time the global is used since globals are just substituted for their definitions where they are used.

Example program:

global A = B;
global B = foo();

fn foo() -> Field {
    A
}

Example error:

error: Dependency cycle found
  ┌─ /Users/user/Code/Noir/noir/short/src/main.nr:2:8
  │
2 │ global B = foo();
  │        - 'B' recursively depends on itself: B -> foo -> A -> B
  │

Additional Context

This is a somewhat longer PR because it also includes a refactoring to use a new GlobalId over StmtId. I found
this necessary to allow referring to globals in cycles where another global may not be resolved yet.

WIP because I still need to:

• Track dependencies within functions
• Update documentation

Documentation*

Check one:

• No documentation needed.
• Documentation included in this PR.
• [Exceptional Case] 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.

[jfecher]

Finished WIP tasks, this PR is now ready for review.

[github-actions]

🚀 Deployed on https://65c513c2b252ee4425b91c96--noir-docs.netlify.app

[signorecello]

Looks great, had to double check we weren't duplicating the docs for globals, but I see you removed that in #4298

I'll still make a suggestion in the doc page if you agree, feel free to merge without it though

Thanks!

[vezenovm]

Could we expand the existing global_consts test or just have a new one entirely for global_const_exprs or something?

[jfecher]

@vezenovm I added a quick example in global_consts