fix(iOS): use bridging header, remove utils wrapper

Author: okwasniewski

packages/react-native-fast-io/ios/BridgingHeader.h

@@ -0,0 +1 @@
+#import <React/RCTUtils.h>

packages/react-native-fast-io/ios/FastIOPrivate/module.modulemap

@@ -1,5 +1,5 @@
 module FastIOPrivate {
-    header "../RCTUtilsWrapper.h"
+    header "../BridgingHeader.h"
     header  "../../cpp/Constants.h"
     export *
 }

packages/react-native-fast-io/ios/HybridFileSystem.swift

@@ -78,7 +78,7 @@ class HybridFileSystem : NSObject, UIDocumentPickerDelegate, HybridFileSystemSpe
         documentPicker.directoryURL = URL(fileURLWithPath: startIn, isDirectory: true)
       }
 
-      guard let vc = RCTUtilsWrapper.getPresentedViewController() else {
+      guard let vc = RCTPresentedViewController() else {
         promise.reject(withError: RuntimeError.error(withMessage: "Cannot present file picker"))
         return
       }