Fix nested buttons on the new architecture

[j-piasecki]

Description

On the new architecture, due to composing RNGestureHandlerButton and RNGestureHandlerButtonComponentView the native view hierarchy wasn't representative of the hierarchy in the React Native. The most outer button would be rendered on top of all the react children, swallowing all the touches and preventing nested buttons from working.

This PR changes the behavior by mounting all children under the actual button view, which should result in the correct native hierarchy.

Test plan

Tested on the example app and on the following code:

import { SafeAreaView, View } from 'react-native';
import {
  GestureHandlerRootView,
  TouchableOpacity,
} from 'react-native-gesture-handler';

export default function App() {
  return (
    <GestureHandlerRootView style={{ flex: 1 }}>
      <SafeAreaView style={{ flex: 1 }}>
        <TouchableOpacity
          onPress={() => {
            console.log('outer press');
          }}>
          <View style={{ width: 200, height: 200, backgroundColor: 'red' }}>
            <TouchableOpacity
              onPress={() => {
                console.log('inner press');
              }}>
              <View
                style={{
                  width: 100,
                  height: 100,
                  backgroundColor: 'blue',
                }}
              />
            </TouchableOpacity>
          </View>
        </TouchableOpacity>
      </SafeAreaView>
    </GestureHandlerRootView>
  );
}

[m-bert]