RN: New TouchableOpacity

Summary:
Launches a new implementation of `TouchableOpacity`.

It is implemented using `Pressability` and extends `React.Component`. Notably, `propTypes` no longer exist.

Changelog:
[General] [Changed] - TouchableOpacity overhauled as a class without propTypes.

Reviewed By: TheSavior

Differential Revision: D18715858

fbshipit-source-id: 06ba5fc7eaacdbb7dc12d1564cc5d04e1a991229

Author: yungsters