chore: reuse the stack code from react navigation 5

The code for the stack is almost the same as v5, with the only differences being the types and the navigation object. To avoid making same changes in 2 places which error-prone, I decided to reuse the same code. Due to the differences, it's not possible to just use it as a dependency, so I followed this approach:
- Copy the source files on post install and apply patches to make it work with React Navigation 4
- When we need to make changes, we can make them in v5 repo and update the version here, most of the time it wouldn't need any extra work
- If we need to make v4 specific changes, we can change the code in vendor/ and then re-generate the patch with `yarn patch`

packages/stack/example/src/ModalStack.tsx

@@ -11,7 +11,7 @@ import {
   createStackNavigator,
   CardStyleInterpolators,
   NavigationStackScreenProps,
-  CardStyleInterpolator,
+  StackCardStyleInterpolator,
 } from 'react-navigation-stack';
 import Animated from 'react-native-reanimated';
 
@@ -21,7 +21,7 @@ const gestureResponseDistance = {
   vertical: Dimensions.get('window').height,
 };
 
-const forVerticalInvertedIOS: CardStyleInterpolator = ({
+const forVerticalInvertedIOS: StackCardStyleInterpolator = ({
   current: { progress },
   layouts: { screen },
 }) => {