Add direction property to OptionsLayout interface

* Add button.iconInsets

* Define iconInsets in Options.ts

* Apply color on button iconImage

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.

This pr adds support for changing tab initialisation mode. Currently bottom tabs are attached together and consequently, their corresponding react root views are created and rendered. This adds lots of stress on the js thread and hiders app start time.

To mitigate this issue, this pr adds support for three modes
* `together` (default, current behaviour) - all tabs are loaded together, adding unnecessary load on the js thread as we're loading invisible views, which leads to increased app start time.
* `afterInitialTab` - Initial tab is loaded first. After it is rendered, other tabs are loaded as well. This should shave a few hunderdish ms from app start time. Since other tabs are loaded after the initial tab is visible, the ui might be unresponsive for a few hunderdish ms as multiple root views (which are typically complex) are being created and attached to hierarchy at once.
* `onSwitchToTab` - initial tab is loaded. Other tabs are loaded when switching to them (tab click or programmatically). While this won't stress js thread after initial tab is rendered, there will be a flicker when entering a tab for the first time as it's ui isn't ready.

* hidesNavigationBarDuringPresentation SearchBar

* Adding hideNavBarOnFocusSearchBar option

* Fixing compilation error

* Code cleanup

* code refactoring

Add missing type interface "waitForRender"

* added a fontFamily to OptionsTopBarButton type
* added modalTransitionStyle to the Options interface

Add typed interface for customTransition

Closes #3664

This property is used to set background color only for components,
unlike backgroundColor which sets color for every type of layout.

Motivation
When a view appears, its options are resolved according to its
currently displayed children. Basically this means that child options
are hoisted to the parent as children can declare options which effect
their parent.
This means that if a component has declared layout.backgroundColor or
if that property was declared in defaultOptions, each view will have a
background color, which might contribute to a significant overdraw.

Until now controlling drawers touch gestures was impossible, drawers received gesture opening touch from the entire screen and that causes collisions with other gestures (which are implemented on the javascript side).

This commit adding modes for how sideMenu drawers gestures will receive opening touch.
```
{
  sideMenu: {
    openGestureMode: 'entireScreen' | 'bezel'
  }
}
```

- `entireScreen`: drawer gesture will trigger drawer opening from the entire screen
- `bezel`: drawer gesture will trigger drawer opening only from the center screen bezel frame

The default didn't change.

Add title alignment to options

This adds an Android-only flag blurOnUnmount, that if true when calling push, pop, showModal, dismisModal, as well as when true on the component's static options(passProps) { ... } return value, will cause RNN to check for any focused views when the component the flag was passed for is being unmounted, and blur said view if it exists, causing not just the view to lose focus, but also the soft keyboard to be dismissed.

We added this to our fork of RNN to tackle issues stemming from an inability to dismiss the soft keyboard on unmounting components, due to the disappear/unmount lifecycle events of the component coming too late for our keyboard dismissal calls to make it across the native<->js bridge before the component was unmounted.

As this functionality is hidden behind a flag and does not alter base functionality, and the issue it seeks to solve might have been encountered by other users of RNN, I figured I might as well submit a PR to see if there is interest in merging this back into the base.

* Removed topBar.transparent and added transparent color support for topBar.background.color

* fix unit tests

* Fix ability to add color for back button

* Change docs because color can be used with iOS too

* Simplify code more

* Move icon logic to one function

* Make returning more clear

* Remove title setting because it is in setBackItem

* Make setBackItem function more clear

* Looks like the if is not needed

* Update RNNBackButtonOptions.m

* Update RNNBackButtonOptions.m

** For iOS only

* Added all styling options and WIP comments

* Completed screen options and layout types

* Added typings to the main entrypoint

* Added buttons too

* Optional fields

* Fixes js unit tests

* Added all styling options and WIP comments

* Completed screen options and layout types

* Added typings to the main entrypoint

* Added buttons too