Switch iOS focus/blur calls to use new commands
Switch iOS focus/blur calls to use new commands

Summary:
Make iOS use Commands instead of UIManager.{focus,blur}. This makes these apis compatible with Fabric and paper at the same time.

Changelog:
[Internal] Switch iOS focus/blur calls to use new commands

Reviewed By: mdvacca

Differential Revision: D19458995

fbshipit-source-id: 8c4aacd41941f54a887aeec1a17d9ce0b6878ab1

hoangpham95/react-native,pandiaraj44/react-native,hammerandchisel/react-native,exponentjs/react-native,janicduplessis/react-native,arthuralee/react-native,myntra/react-native,hoangpham95/react-native,exponent/react-native,arthuralee/react-native,facebook/react-native,javache/react-native,hammerandchisel/react-native,janicduplessis/react-native,exponent/react-native,myntra/react-native,hammerandchisel/react-native,pandiaraj44/react-native,facebook/react-native,facebook/react-native,facebook/react-native,myntra/react-native,myntra/react-native,pandiaraj44/react-native,exponentjs/react-native,janicduplessis/react-native,janicduplessis/react-native,hoangpham95/react-native,javache/react-native,janicduplessis/react-native,myntra/react-native,hammerandchisel/react-native,pandiaraj44/react-native,arthuralee/react-native,hammerandchisel/react-native,javache/react-native,exponentjs/react-native,javache/react-native,pandiaraj44/react-native,myntra/react-native,hoangpham95/react-native,exponent/react-native,arthuralee/react-native,myntra/react-native,exponentjs/react-native,hammerandchisel/react-native,hoangpham95/react-native,exponentjs/react-native,facebook/react-native,exponent/react-native,arthuralee/react-native,janicduplessis/react-native,javache/react-native,exponent/react-native,exponentjs/react-native,janicduplessis/react-native,facebook/react-native,hammerandchisel/react-native,hammerandchisel/react-native,hoangpham95/react-native,facebook/react-native,javache/react-native,exponent/react-native,javache/react-native,facebook/react-native,javache/react-native,exponent/react-native,facebook/react-native,exponentjs/react-native,pandiaraj44/react-native,hoangpham95/react-native,exponentjs/react-native,pandiaraj44/react-native,janicduplessis/react-native,myntra/react-native,javache/react-native,myntra/react-native,hoangpham95/react-native,exponent/react-native,pandiaraj44/react-native