Update react-native-windows to new architecture

[KGGrande]

New Arch RNW apps will not build unless updated.

...\node_modules\react-native-windows\PropertySheets\external\Microsoft.ReactNative.Uwp.Common.props(12,5): error : Property 'RnwNewArch' was set to 'true'. Projects built against Microsoft.ReactNative.Uwp require RnwNewArch to be 'false'. [...\node_modules\@nozbe\watermelondb\native\windows\WatermelonDB\WatermelonDB.vcxproj]. Check your build configuration.
Command failed. Re-run the command with --logging for more information.

https://github.com/microsoft/react-native-windows/wiki/Upgrading-a-React-Native-Windows-TurboModule-to-use-the-New-Architecture

[gmacmaster]

+1