Summary:
## Changelog:
[Internal] - Refactor Android/iOS/C++ TurboModule examples
~~This makes sure that both native and pure C++ (NativeCxx) TurboModule examples could be run from the Catalyst app.~~
EDIT: See the discussion - this removes the `Playground (NativeModules)` app from Catalyst, as it's already available from the `RNTester Browser` and doesn't provide the C++ counterpart.
Also, there are some tweaks and code factoring in styles, to make it all fit on the screen nicely.
Reviewed By: javache
Differential Revision: D43605250
fbshipit-source-id: 44ee694660f3ad524b8362149ebe617ee495225e
Ruslan Shestopalyuk