Upgrade Picker 3P Module to support for fabric Application

[sharath2727]

Upgrade Picker 3P Module to support for fabric Application

[anupriya13]

• Task 1: Upgrade RNW from 0.76 to 0.81 and fix errors
• Task 2: Add new arch implementation and boiler plate code + Fix example and test E2E basic with 0.81 new arch
• Task 3: Add Stubs from spec to .h and fix errors in example app
• Task 3: Implement XAML requirements for picker in new arch
• Task 4: Update example sample app and testing
• Task 5: Cleanup, refactor and publish PR

Refer PR: react-native-picker/picker#664

[anupriya13]

PR: react-native-picker/picker#664