When updating buttons with mergeOptions, existing custom buttons are unmounted and then recreated. This commit adds an optimisation which prevents the react components from being recreated.
To avoid unnecessary recreation, add an `id` to the component. If an existing react view is found for that id, it will be reused.

* Fix button with react component doesn't get unmounted

* Test e2e only on iOS

Break all the PRs :(

iOS and Android code base used different naming conventions - this commit aims to unify naming conventions. I probably missed a few properties here and there so this will be an ongoing effort.

* Remove currentLeaf

* Fix resolve options

* Remove irrelevant test

* Remove RNNRootViewController clear background color

* Fix title with subtitle options

* Layout changes

* WIP

* Revert "Layout changes"

This reverts commit 4da8cfbd12.

* Clean topBar.component and topBar.background.component when not needed

* Move custom components login from viewController to presenters

* Change waitForRender and enabled property from primitive bool to Bool object

* Fix ios unit tests

* Add unit tests

* Remove RNNReactView observer when view ready

* Load react components from component manager

* Remove createCustomReactView duplication

* Handle render children in each Layout

* Wait for navigation presenter components render, refactor RNNTitleViewHelper

* Fix unit tests

* Add waitForRender for custom react components

* Fixes e2e