Fix generated EventEmitter code for nested objects in arrays. (#47514)

Summary:
This PR fixes the code for generating EventEmitter C++ code in case nested objects in arrays are used.

```typescript
export interface NativeProps extends ViewProps {
  onEvent: DirectEventHandler<
    Readonly<{
      payloadArray: Readonly<
        {
          obj: Readonly<{ str: string }>
        }[]
      >
    }>
  >;
}

export default codegenNativeComponent<NativeProps>('SomeComponent');
```

In this case the generated `EventEmitters.cpp` code would contain:

```c
obj.setProperty(runtime, "str", payloadArrayValue,obj.str);
```

while

```c
obj.setProperty(runtime, "str", payloadArrayValue.obj.str);
```

is expected.

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[GENERAL] [FIXED] - Codegen: Support nested objects in arrays

Pull Request resolved: #47514

Test Plan: Tested with the reproduction case above to verify correct output.

Reviewed By: christophpurrer

Differential Revision: D65884936

Pulled By: elicwhite

packages/react-native-codegen/e2e/__tests__/components/__snapshots__/GenerateEventEmitterCpp-test.js.snap

@@ -168,7 +168,7 @@ void EventNestedObjectPropsNativeComponentViewEventEmitter::onChange(OnChange $e
         auto arrayOfObjectsObject = jsi::Object(runtime);
         {
     auto value = jsi::Object(runtime);
-    value.setProperty(runtime, \\"str\\", arrayOfObjectsValue,value.str);
+    value.setProperty(runtime, \\"str\\", arrayOfObjectsValue.value.str);
     arrayOfObjectsObject.setProperty(runtime, \\"value\\", value);
   }
         arrayOfObjects.setValueAtIndex(runtime, arrayOfObjectsIndex++, arrayOfObjectsObject);

packages/react-native-codegen/src/generators/components/GenerateEventEmitterCpp.js

@@ -104,7 +104,7 @@ function generateSetter(
 ) {
   const eventChain = usingEvent
     ? `$event.${[...propertyParts, propertyName].join('.')}`
-    : [propertyParts, propertyName].join('.');
+    : [...propertyParts, propertyName].join('.');
   return `${variableName}.setProperty(runtime, "${propertyName}", ${valueMapper(
     eventChain,
   )});`;
@@ -157,7 +157,7 @@ function generateArraySetter(
 ): string {
   const eventChain = usingEvent
     ? `$event.${[...propertyParts, propertyName].join('.')}`
-    : [propertyParts, propertyName].join('.');
+    : [...propertyParts, propertyName].join('.');
   const indexVar = `${propertyName}Index`;
   const innerLoopVar = `${propertyName}Value`;
   return `