feat: Brillig IR refactor (#5233)

Split brillig IR in low level instructions and higher level codegen
files that compose the instructions and restrict visibilities. This
should not have any business logic change. This also fixes debug_show by
only printing the low level instructions, previously we were printing
both the high level codegen and the low level instructions and it was a
mess to read.

noir/noir-repo/compiler/noirc_evaluator/src/brillig/brillig_gen/brillig_black_box.rs

@@ -167,7 +167,7 @@ pub(crate) fn convert_black_box_call(
             ) = (function_arguments, function_results)
             {
                 let message_hash = convert_array_or_vector(brillig_context, message, bb_func);
-                let signature = brillig_context.array_to_vector(signature);
+                let signature = brillig_context.array_to_vector_instruction(signature);
                 brillig_context.black_box_op_instruction(BlackBoxOp::SchnorrVerify {
                     public_key_x: public_key_x.address,
                     public_key_y: public_key_y.address,
@@ -368,7 +368,7 @@ fn convert_array_or_vector(
     bb_func: &BlackBoxFunc,
 ) -> BrilligVector {
     match array_or_vector {
-        BrilligVariable::BrilligArray(array) => brillig_context.array_to_vector(array),
+        BrilligVariable::BrilligArray(array) => brillig_context.array_to_vector_instruction(array),
         BrilligVariable::BrilligVector(vector) => *vector,
         _ => unreachable!(
             "ICE: {} expected an array or a vector, but got {:?}",