* Remove main window backgroundColor
* Better interface for TopBarPresenter

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.

When mergeOptions was called without a title component, existing component was undesirably removed.
This commit changes how component is removed when mergeOptions is called. It will now be removed if a component is not defined and title is defined in mergeOptions.
Fixes #5628

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.

* Enabled option was wrongly consumed after it was merged. That meant that the next time SideMenu options were applied, the wrong enabled value was applied
* supportedInterfaceOrientations didn't take default orientation value into account
* mergeOptions didn't save the new options in the ViewControllers current options
* SideMenu always returned the centre ViewController as the current child and didn't take open SideMenu into account

Fixes #5444

Merging TopBar title, buttons and status bar options is broken on iOS in 3.1.1.
Parent options aren't resolved properly and default options aren't regarded when they should be.

This commit adds initial support for passing null as a valid value for color properties.
When a color property is applied, if it wasn't specified then the default color is applied. Now, when null is passed, no color will be applied
leaving the last color applied as is.

This is useful when showing an Overlay and you'd like to keep the current StatusBar color unaffected. Another usecase would be when you'd like to avoid coloring an icon in BottomTabs.

Add support for dot indicator to BottomTabs.

This approach is still not ideal as it assumes there's a visible stack somewhere in the Hierarchy.
It's better than the current implementation so I'm pushing it and will reiterate in the future if needed.

* Fix top bar layout frame, Closes #5003

* Set layout child view controllers on initialization

* Remove duplicate initWithLayoutInfo: function

* Stop manually manage viewControllers store, Iterate layout instead

* Update RNNCommandsHandlerTest.m

* Explicitly attach and detach viewControllers in store
* Stop registering components in commands handler