Add iOS support for `bottomTabs.attachMode`.
This property controls when BottomTabs children are attached to hierarchy and when their React views are created.

By default, RNN attaches all children at the same time which might impact loading time as a few screens are instantiated at once.
Using `afterInitialTab` or `onSwitchToTab` generally leads to improved start up time.

* Migrate project to workspace

This commit moves all unit tests to the playground workspace

* Fix ios unit tests

* Build pods before testing

* Build typescript before running iOS tests

* Remove xcode 10 support

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.

* created RNNNavigationOptions

* created RNNRootViewControllerTest and added a test for the topBarBackgroundColor style

* working

* process navigationOptions colors

* created a test for new RNNRootViewController functionality

* changed RNNRootViewController to init with name, navigationOptions and container id, instead of node

* changed RNNRootViewController to get a new type - RNNavigationOptions

* refactored statusBarHidden test and implementation, all tests pass

* added setup to RNNRootViewControllerTest.m and refactored tests

* added test for title and implemented static title

* minor fixes

* removed redundant eslint config