Remove Paper (ReactNativeRenderer) files

Summary:
All Meta apps have migrated to Fabric, so the Paper renderer files are no longer needed.

This commit removes:
- ReactNativeRenderer-dev.js, ReactNativeRenderer-dev.fb.js
- ReactNativeRenderer-prod.js, ReactNativeRenderer-prod.fb.js
- ReactNativeRenderer-profiling.js, ReactNativeRenderer-profiling.fb.js
- ReactNative.js shim

Also updates:
- AppRegistryImpl.js: unmountApplicationComponentAtRootTag is now a no-op with error log
- MyLegacyViewNativeComponent.js: Use findNodeHandle from react-native instead of deleted shim

Differential Revision: D101353118

Author: rubennorte