RN: Implement `sendAccessibilityEvent` in RN Renderer that proxies between Fabric/non-Fabric (#20554)

* RN: Implement `sendAccessibilityEvent` on HostComponent

Implement `sendAccessibilityEvent` on HostComponent for Fabric and non-Fabric RN.

Currently the Fabric version is a noop and non-Fabric uses
AccessibilityInfo directly. The Fabric version will be updated once
native Fabric Android/iOS support this method in the native UIManager.

* Move methods out of HostComponent

* Properly type dispatchCommand and sendAccessibilityEvent handle arg

* Implement Fabric side of sendAccessibilityEvent

* Add tests: 1. Fabric->Fabric, 2. Paper->Fabric, 3. Fabric->Paper, 4. Paper->Paper

* Fix typo: ReactFaricEventTouch -> ReactFabricEventTouch

* fix flow types

* prettier