Add more type and mutability checks

[edg-l]

Checks if a variable is declared mutable and if not, if its being mutated.

Checks for valid mutable borrows (but doesnt check for multiple mutable borrows yet).

[github-actions[bot]]

Benchmarking factorial

Compiling factorial (factorial.con) Finished release in 29.635568ms Running 5000000 iterations Using input value: 20 Concrete Result = 2432902008176640000 Time taken : 59.21 ms Rust Result = 2432902008176640000 Time taken : 60.12 ms

Benchmarking fib

Compiling fib (fib.con) Finished release in 25.358815ms Running 5000 iterations Using input value: 20 Concrete Result = 6765 Time taken : 136.23 ms Rust Result = 6765 Time taken : 85.19 ms

[codecov-commenter]

Codecov Report

Attention: Patch coverage is 58.92857% with 46 lines in your changes are missing coverage. Please review.

Project coverage is 58.44%. Comparing base (bd93e07) to head (bfc07ea).

Files	Patch %	Lines
crates/concrete_check/src/lib.rs	0.00%	40 Missing :warning:
crates/concrete_ir/src/lib.rs	87.50%	4 Missing :warning:
crates/concrete_ir/src/lowering.rs	95.00%	2 Missing :warning:

Additional details and impacted files

```diff @@ Coverage Diff @@ ## main #124 +/- ## ========================================== - Coverage 58.64% 58.44% -0.20% ========================================== Files 25 25 Lines 4258 4361 +103 ========================================== + Hits 2497 2549 +52 - Misses 1761 1812 +51 ```

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