Add assert_on_const lint

[integraledelebesgue]

Closes #509

The implementation is identical to #388, with an additional check that fixes the panic:

cairo-lint/src/lints/assert_on_const.rs

Lines 183 to 186 in f4c53c6

	// `LoweringGroup::lowered_body` can only be applied to functions that have no generic parameters in scope.
	if has_generic_params(db, function_with_body_id) {
	return None;
	}

Additional tests verify the proper behaviour in problematic cases (including the repro from the issue):

cairo-lint/tests/assert_on_const/mod.rs

Lines 96 to 132 in f4c53c6

	/// A trait function with a default body which is not fully concrete (its impl is the abstract `Self` impl)
	/// but has no generic parameters, so the lint should handle it.
	const BOOL_CONST_IN_TRAIT_FUNCTION: &str = r#"
	trait Trait {
	fn foo() {
	assert!(true, "message");
	}
	}
	"#;
	/// A trait function with a default body which is not fully concrete (its impl is the abstract `Self` impl)
	/// and additionally pulls an associated type into a body variable.
	/// Lint should fail gracefully when trying to retrieve the lowering of the function and not panic.
	const BOOL_CONST_IN_TRAIT_FUNCTION_WITH_ASSOCIATED_TYPE: &str = r#"
	trait Trait {
	type Item;
	fn item() -> Self::Item;
	fn foo() {
	let _item = Self::item();
	assert!(true, "message");
	}
	}
	"#;
	/// A trait function which is not fully concrete and has a generic parameter - it silently takes a generic impl of PartialEq as a param.
	/// Lint should fail gracefully when trying to retrieve the lowering of the function and not panic.
	const BOOL_EXPR_NOT_FULLY_CONCRETE_FUNCTION: &str = r#"
	pub trait MyTrait<T> {
	fn foo<+PartialEq<T>>(a: @T, b: @T);
	}
	impl MyTraitImpl<T> of MyTrait<T> {
	fn foo<+PartialEq<T>>(a: @T, b: @T) {
	assert!(a == b, "message");
	}
	}
	"#;

[Arcticae]

Next time pls revert the commit + add one on top with the changes - it will make it easier to review 😄