More codegen (control flow, if else, while)

[edg-l]

Adds:

• If support
• While support
• Integration tests
• Some cleanup

This adds support of if statements, which let us already be able to run the following factorial program:

mod Simple {
    fn main() -> i64 {
        return factorial(4);
    }

    fn factorial(n: i64) -> i64 {
        let zero: i64 = 0;
        if n == zero {
            return 1;
        } else {
            return n * factorial(n - 1);
        }
    }
}

Checking the result with bash exit code (needs to be a low value otherwise bash shows 0 because shell limitations)

concrete on  if_impl [$✘!?] via 🦀 v1.75.0 
❯ ./build_artifacts/factorial_if 

concrete on  if_impl [$✘!?] via 🦀 v1.75.0 
❯ echo $?
24

While is also implemented:

mod Simple {
    fn main() -> i64 {
        return my_func(4);
    }

    fn my_func(times: i64) -> i64 {
        let mut n: i64 = times;
        let mut result: i64 = 1;

        while n > 0 {
            result = result + result;
            n = n - 1;
        }

        return result;
    }
}

[codecov-commenter]

Codecov Report

Attention: 133 lines in your changes are missing coverage. Please review.

Comparison is base (771662e) 14.55% compared to head (e67c308) 68.74%.

Files	Patch %	Lines
crates/concrete_parser/src/error.rs	0.00%	82 Missing ⚠️
crates/concrete_codegen_mlir/src/codegen.rs	92.26%	28 Missing ⚠️
crates/concrete_driver/src/lib.rs	0.00%	13 Missing ⚠️
crates/concrete_session/src/lib.rs	0.00%	6 Missing ⚠️
crates/concrete_codegen_mlir/src/context.rs	33.33%	4 Missing ⚠️

Additional details and impacted files

@@             Coverage Diff             @@
##             main      #77       +/-   ##
===========================================
+ Coverage   14.55%   68.74%   +54.18%     
===========================================
  Files          27       27               
  Lines         886     1187      +301     
===========================================
+ Hits          129      816      +687     
+ Misses        757      371      -386     

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