Add OneSignal.Notifications.permissionNative

* Add permissionNative which tells if it's provisional, ephemeral, denied, authorized etc
* Expose enum OSNotificationPermission which has 5 values

Author: nan-li

iOS_SDK/OneSignalSDK/OneSignalNotifications/OSNotificationsManager.h

@@ -36,11 +36,12 @@ typedef void (^OSNotificationWillShowInForegroundBlock)(OSNotification * _Nonnul
 typedef void (^OSNotificationOpenedBlock)(OSNotificationOpenedResult * _Nonnull result);
 
 /**
- Public API.
+ Public API for the Notifications namespace.
  */
 @protocol OSNotifications <NSObject>
 + (BOOL)permission NS_REFINED_FOR_SWIFT;
 + (BOOL)canRequestPermission NS_REFINED_FOR_SWIFT;
++ (OSNotificationPermission)permissionNative NS_REFINED_FOR_SWIFT;
 + (void)setNotificationWillShowInForegroundHandler:(OSNotificationWillShowInForegroundBlock _Nullable)block;
 + (void)setNotificationOpenedHandler:(OSNotificationOpenedBlock _Nullable)block;
 + (void)requestPermission:(OSUserResponseBlock _Nullable )block;

iOS_SDK/OneSignalSDK/OneSignalNotifications/OSNotificationsManager.m

@@ -232,6 +232,10 @@ + (BOOL)canRequestPermission {
     return !self.currentPermissionState.answeredPrompt;
 }
 
++ (OSNotificationPermission)permissionNative {
+    return self.currentPermissionState.status;
+}
+
 + (void)requestPermission:(OSUserResponseBlock)block {
     // return if the user has not granted privacy permissions
     if ([OSPrivacyConsentController shouldLogMissingPrivacyConsentErrorWithMethodName:@"requestPermission:"])

iOS_SDK/OneSignalSDK/Source/OneSignalSwiftInterface.swift

@@ -93,6 +93,10 @@ public extension OSNotifications {
         return __canRequestPermission()
     }
 
+    static var permissionNative: OSNotificationPermission {
+        return __permissionNative()
+    }
+    
     static func registerForProvisionalAuthorization(_ block: OSUserResponseBlock?) {
         return __register(forProvisionalAuthorization: block)
     }