[fabric] TextInput should get focus with autoFocus prop

Summary:
**Context**

- TextInput focus prop was not wired up for Fabric

**Change**

- Focus the text input if `autofocus={true}`

Test Plan: Tested in top of stack

Reviewers: lefever, #rn-desktop

Reviewed By: lefever

Differential Revision: https://phabricator.intern.facebook.com/D54880714

Author: shwanton

packages/react-native/React/Fabric/Mounting/ComponentViews/TextInput/RCTTextInputComponentView.mm

@@ -142,7 +142,12 @@ - (void)didMoveToWindow
     if (props.autoFocus) {
 #if !TARGET_OS_OSX // [macOS]
       [_backedTextInputView becomeFirstResponder];
-#endif // [macOS]
+#else // [macOS
+      NSWindow *window = [_backedTextInputView window];
+      if (window) {
+        [window makeFirstResponder:_backedTextInputView.responder];
+      }
+#endif // macOS]
       [self scrollCursorIntoView];
     }
     _didMoveToWindow = YES;