Add types for onFocusCapture/onBlurCapture

Summary:
Add capture-phase focus events to the type system, for use in the refactored VirtualizedList https://github.com/facebook/react-native/pull/32646/files

Tracking the last focused child is done via focus events. Focus events are bubbling (vs direct events like onLayout), and are given both a "capture" phase, and "bubbling phase", like DOM events on the web. https://stackoverflow.com/questions/4616694/what-is-event-bubbling-and-capturing

The VirtualizedList change wants to know if a child will receive focus. This is not possible to reliably capture in the bubbling phase, since a child may stop propagation.

See react-native-community/discussions-and-proposals#335 (comment) for some discussion with Scott Kyle about this issue back in the day

This is done by convention in React by adding a "capture" variant of the `onXXX` method. For all platforms I've seen with focus events, these map the `topFocus` native event to `onFocus` for bubbling phase, and `onFocusCapture` for capture phase. See https://reactjs.org/docs/events.html#supported-events

Changelog:
[General][Added] - Add types for onFocusCapture/onBlurCapture

Reviewed By: javache

Differential Revision: D38013861

fbshipit-source-id: 7bda22e1a4d5e36ac5e34e804abf6fb318a41baf

Libraries/Components/View/ViewPropTypes.js

@@ -33,11 +33,6 @@ import type {
 export type ViewLayout = Layout;
 export type ViewLayoutEvent = LayoutEvent;
 
-type BubblingEventProps = $ReadOnly<{|
-  onBlur?: ?(event: BlurEvent) => mixed,
-  onFocus?: ?(event: FocusEvent) => mixed,
-|}>;
-
 type DirectEventProps = $ReadOnly<{|
   /**
    * When `accessible` is true, the system will try to invoke this function
@@ -105,6 +100,13 @@ type PointerEventProps = $ReadOnly<{|
   onPointerUpCapture?: ?(e: PointerEvent) => void,
 |}>;
 
+type FocusEventProps = $ReadOnly<{|
+  onBlur?: ?(event: BlurEvent) => void,
+  onBlurCapture?: ?(event: BlurEvent) => void,
+  onFocus?: ?(event: FocusEvent) => void,
+  onFocusCapture?: ?(event: FocusEvent) => void,
+|}>;
+
 type TouchEventProps = $ReadOnly<{|
   onTouchCancel?: ?(e: PressEvent) => void,
   onTouchCancelCapture?: ?(e: PressEvent) => void,
@@ -394,11 +396,11 @@ type IOSViewProps = $ReadOnly<{|
 |}>;
 
 export type ViewProps = $ReadOnly<{|
-  ...BubblingEventProps,
   ...DirectEventProps,
   ...GestureResponderEventProps,
   ...MouseEventProps,
   ...PointerEventProps,
+  ...FocusEventProps,
   ...TouchEventProps,
   ...AndroidViewProps,
   ...IOSViewProps,