Add threadIdentifier to local notifications

[holden-caulfield]

Feature Request

Add the possibility for local notifications (e.g. as in PushNotificationIOS.presentLocalNotification()) to include threadIdentifier on its details.

Why it is needed

Using the threadIdentifier allows to group notifications together on the notification center

Possible implementation

I'm happy to send a PR, it seems to me it should be as simple as adding the parsing of that parameter on the UILocalNotification object. This would be an iOS only property

@implementation RCTConvert (UILocalNotification)

+ (UILocalNotification *)UILocalNotification:(id)json
{
  NSDictionary<NSString *, id> *details = [self NSDictionary:json];
  ....
  if (details[@"threadIdentifier"]) {
    notification.threadIdentifier = [RCTConvert NSString:details[@"threadIdentifier"]];
  }
  return notification;
}

(Adding the if statement because I guess that if not explicitly set, iOS sets a "smart" threadIdentifier based on application, title, etc.)

Code sample

PushNotificationIOS.presentLocalNotification({
// should also work with PushNotificationIOS.scheduleLocalNotification
   alertTitle: "My threaded local notification"
   alertBody: "This will be threaded",
   threadIdentifier: "SomeIdentifier"
})

[Naturalclar]

@holden-caulfield Thanks for raising the issue!
Support for threadId in local notification has been added in v1.7.0 🎉