feat: Allow resolved types in constructors

[jfecher]

Description

Problem*

From a private ask by Jan

Summary*

Allows already resolved types in constructor expressions. These types are the result of comptime code and simplify creating constructors by not requiring you to specify the full path to an unresolved type - which you may not be able to get at all.

Additional Context

Allows, e.g:

fn main() {
    // Unquotes to `let _ = Foo {}` which resolves despite Foo not being in scope
    let _ = my_macro!();
}

mod foo {
    pub struct Foo {}

    comptime fn my_macro() {
        // quote Foo without needing to specify the full path to it in the quoted snippet
        let typ = quote[Foo].as_type();
        quote[$typ {}]
    }
}

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]

⚠️ Performance Alert ⚠️

Possible performance regression was detected for benchmark 'Test Suite Duration'.
Benchmark result of this commit is worse than the previous benchmark result exceeding threshold 1.20.

Benchmark suite	Current: 0432da7	Previous: 4d37fb0	Ratio
noir-lang_noir_string_search_	1 s	0 s	+∞
noir-lang_mimc_	1 s	0 s	+∞
AztecProtocol_aztec-packages_noir-projects_noir-protocol-circuits_crates_parity-lib	3 s	2 s	1.50

This comment was automatically generated by workflow using github-action-benchmark.

CC: @TomAFrench