fix(ssa refactor): fix bad constant type caching

[joss-aztec]

Description

Problem*

Bad type information was used when creating a constant that matched a previously cached constant without considering its type

Summary*

Cache constants by both numeric value and type

Example

fn main(x: u2) -> pub u2 {
    0 - x
}

Before:

Initial SSA:
fn main f0 {
  b0(v0: u2):
    v2 = sub unit 0, v0
    return v2
}

After:

Initial SSA:
fn main f0 {
  b0(v0: u2):
    v2 = sub u2 0, v0
    return v2
}

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.