The bottomTab settings were not being properly applied if a SplitView
controller was nested. Part of this seems to be that the 'options' for
SplitView were in their V1 form, i.e. they did not have access to the
full topBar/bottomTab/etc.

I refactored the options to be in their own subsettings. NOTE: the
settings for splitView are not being applied currently -- they weren't
before and they still are not now.

With access to the full options now, I was able to change
RNNSplitViewController to properly override
willMoveToParentViewController to get the bottomTab icon to properly
show up.

* Renamed RNNRootViewProtocol to RNNParentProtocol and added RNNLeafProtocol

* fixed unit test

* Better options resolving

* Revert "Revert "Refactor options (#3962)""

This reverts commit c266041b85.

* Revert "Revert "Fixes shared element transition""

This reverts commit 005f039f7c.

* Revert "Revert "Adresses #3963 - stack options applied to children""

This reverts commit be09cb0e9a.

* Revert "Revert "Added unit test coverage for RNNNavigationController""

This reverts commit 199cebd221.

* Merge stack options

This commits adds support for merging stack options by the stack’s componentId

Also while I’m at it - use fade animation when setting root

* Merge BottomTabs options

Merge BottomTabs options when calling mergeOptions with BottomTabs componentId

* Fixes options

* Work in progress

* Arbitary changes

* Improvements on API

* Cleanup RNNSplitViewController, allow mergeOptions

* Added documentation and better playground example

* Adding tests for coverage

* Find out why this test is failing.

* Only show split view on iOS

* Add test back in