chore: remove dependency on react-navigation@v4 & unify test example apps

[kkafar]

Description

I removed dependency on react-navigation@v4 in TestsExample & copied tests from TestsExample to FabricTestsExample (all tests should work now, as support for reanimated was added here; maybe except FullWindowOverlay - WIP, PR will come soon)

Changes

• Removed react-navigation & react-navigation-stack dependency from TestsExample/package.json & ran yarn install
• Copied already not present tests to FabricTestsExample
• Removed Test765 as it depended on react-navigation@v4

Test code and steps to reproduce

Open FabricTestExample app

Checklist

• Included code example that can be used to test this change
• Updated TS types
• Updated documentation:
  • https://github.com/software-mansion/react-native-screens/blob/main/guides/GUIDE_FOR_LIBRARY_AUTHORS.md
  • https://github.com/software-mansion/react-native-screens/blob/main/native-stack/README.md
  • https://github.com/software-mansion/react-native-screens/blob/main/src/types.tsx
  • https://github.com/software-mansion/react-native-screens/blob/main/src/native-stack/types.tsx
• Ensured that CI passes