Summary:
Part of: #23313.
This moves the `RCTTest` lib from `Libraries/RCTTest` to `RNTester/RCTTest`. This also removes `takeSnapshot` from React Native, and implements it as a standalone module in RNTester called `ScreenshotManager`.
[General] [Removed] - RCTTest & ReactNative.takeSnapshot
Pull Request resolved: https://github.com/facebook/react-native/pull/23721
Differential Revision: D14434796
Pulled By: PeteTheHeat
fbshipit-source-id: d6e103a0ea0b6702701cdb5ce8449163ca4628ce
ericlewis