Simplify bytecode circuit assignment (#1397)

### Description

We simplify the assignment logic in the bytecode circuit by reducing the
number of function arguments. The reduction is achieved by

1. Construct IsZero Chips early and make them a part of the circuit
struct so that they don't stay with the function arguments.
2. Create a new row struct that carries all the relevant data.

### Issue Link

This would be part of #1391. 

### Type of change

- [x] Bug fix (non-breaking change which fixes an issue)
- [ ] New feature (non-breaking change which adds functionality)
- [ ] Breaking change (fix or feature that would cause existing
functionality to not work as expected)
- [ ] This change requires a documentation update

### Rationale

- I avoid using `BytecodeRow` in the `bytecode_unroller` since they are
part of the future simplification plan.


### How Has This Been Tested?

Sent to the CI and pray.

gadgets/src/is_zero.rs

@@ -51,11 +51,11 @@ impl<F: Field> IsZeroConfig<F> {
     }
 }
 
+#[derive(Debug, Clone)]
 /// Wrapper arround [`IsZeroConfig`] for which [`Chip`] is implemented.
 pub struct IsZeroChip<F> {
     config: IsZeroConfig<F>,
 }
-
 #[rustfmt::skip]
 impl<F: Field> IsZeroChip<F> {
     /// Sets up the configuration of the chip by creating the required columns
@@ -105,6 +105,11 @@ impl<F: Field> IsZeroChip<F> {
     pub fn construct(config: IsZeroConfig<F>) -> Self {
         IsZeroChip { config }
     }
+
+    /// Annotates columns of this gadget embedded within a circuit region.
+    pub fn annotate_columns_in_region(&self, region: &mut Region<F>, prefix: &str) {
+      self.config.annotate_columns_in_region(region, prefix)
+    }
 }
 
 impl<F: Field> IsZeroInstruction<F> for IsZeroChip<F> {