Add onEventHandler block handler to handle all fired events.

[Romick2005]

Init CallKeep on native site, not on JS.
Pass a function that will called at any call reported event. And make them public via native interface like: RNCallKeepPerformEndCallAction, RNCallKeepDidDisplayIncomingCall, ... etc

[sboily]

Hello, can you explain a little bit this PR please? Thank you!

[Romick2005]

All of that was done due to the issue that on slow devices the event "RNCallKeepDidLoadWithEvents" was not filled with all fired events. So in case when person A calling to Person B (app on Person B device is closed/killed) and Person B rejects the call there was no way to inform person A that call was rejected, but on native part I saw RNCallKeepPerformEndCallAction, but not on js side event not in RNCallKeepDidLoadWithEvents. So I decided to send http request directly from native code and that is why I need access the the event name and separate method to setup CallKeep.
So in my case I need more exclusive access to the library. That is why I add additional callback withEventHandler for withEventHandler:

  [callKeep initCallKitProvider: settings
    // withEventHandler: nil
    withEventHandler: ^(NSString *eventName, id data) {

      #ifdef DEBUG
        NSLog (@"[RNCallKeep][setup] event eventName = %@, data = %@", eventName, data);
      #endif

      if (eventName == RNCallKeepHandleStartCallNotification) {
        NSLog (@"[RNCallKeep][withEventHandler] RNCallKeepHandleStartCallNotification");
      } else if (eventName == RNCallKeepDidReceiveStartCallAction) {
        NSLog (@"[RNCallKeep][withEventHandler] RNCallKeepDidReceiveStartCallAction");
      } else if (eventName == RNCallKeepPerformAnswerCallAction) {
        startTimeInSeconds = (long) [[NSDate date] timeIntervalSince1970];
        NSLog (@"[RNCallKeep][withEventHandler] RNCallKeepPerformAnswerCallAction");
      } else if (eventName == RNCallKeepPerformEndCallAction) {

        // Prepare data for http request
        NSString *callUUID = data[@"callUUID"];
        NSDictionary *payload = callUUIDCallDataMap[callUUID][@"payload"];

        NSDictionary *parameters = @{
          @"callUUID": callUUID,
          @"reasonId": @6
        };

        // Send http delete request to reject call
        NSData *callEndData = [NSJSONSerialization dataWithJSONObject: parameters options: NSJSONWritingPrettyPrinted error: nil];
        NSMutableURLRequest *request = [[NSMutableURLRequest alloc] init];
        [request setURL: [NSURL URLWithString: cancelUrl]];
        [request setHTTPMethod: @"DELETE"];
        [request addValue: @"application/json" forHTTPHeaderField: @"Content-Type"];
        NSString *postLength = [NSString stringWithFormat: @"%lu", [callEndData length]];
        [request setValue: postLength forHTTPHeaderField: @"Content-Length"];
        [request setHTTPBody: callEndData];
        [[[NSURLSession sharedSession] dataTaskWithRequest: request] resume];
        [callUUIDCallDataMap removeObjectForKey: callUUID];

        NSLog (@"[RNCallKeep][withEventHandler] RNCallKeepPerformEndCallAction");

        // [NSThread sleepForTimeInterval:2.0f];
      } else if (eventName == RNCallKeepDidActivateAudioSession) {
        NSLog (@"[RNCallKeep][withEventHandler] RNCallKeepDidActivateAudioSession");
      } else if (eventName == RNCallKeepDidDeactivateAudioSession) {
        NSLog (@"[RNCallKeep][withEventHandler] RNCallKeepDidDeactivateAudioSession");
      } else if (eventName == RNCallKeepDidDisplayIncomingCall) {
        NSString *callUUID = data[@"callUUID"];
        [callUUIDCallDataMap setObject: data forKey: callUUID];

        NSLog (@"[RNCallKeep][withEventHandler] RNCallKeepDidDisplayIncomingCall");
      } else if (eventName == RNCallKeepDidPerformSetMutedCallAction) {
        NSLog (@"[RNCallKeep][withEventHandler] RNCallKeepDidPerformSetMutedCallAction");
      } else if (eventName == RNCallKeepPerformPlayDTMFCallAction) {
        NSLog (@"[RNCallKeep][withEventHandler] RNCallKeepPerformPlayDTMFCallAction");
      } else if (eventName == RNCallKeepDidToggleHoldAction) {
        NSLog (@"[RNCallKeep][withEventHandler] RNCallKeepDidToggleHoldAction");
      } else if (eventName == RNCallKeepProviderReset) {
        NSLog (@"[RNCallKeep][withEventHandler] RNCallKeepProviderReset");
      } else if (eventName == RNCallKeepCheckReachability) {
        NSLog (@"[RNCallKeep][withEventHandler] RNCallKeepCheckReachability");
      } else if (eventName == RNCallKeepDidLoadWithEvents) {
        NSLog (@"[RNCallKeep][withEventHandler] RNCallKeepDidLoadWithEvents");
      } else {
        NSLog (@"[RNCallKeep][withEventHandler] Event %@not found.", eventName);
      }
    }
  ];

  return YES;
}

Also I moved CallKeep setup to the native part to have everything under control and to not set up it twice:

 // Callkeep setup
  // We have to set appName as settings for CallKeep in standardUserDefaults, because we may not call RNCallKeep.setup(options) on JS side
  NSDictionary *settings = [[NSUserDefaults standardUserDefaults] dictionaryForKey:@"RNCallKeepSettings"];

  NSBundle *bundle = [NSBundle mainBundle];
  NSDictionary *info = [bundle infoDictionary];

  NSMutableDictionary<NSString *, NSMutableDictionary *> *callUUIDCallDataMap =  [[NSMutableDictionary alloc] init];

  settings = @{
    @"appName": [info objectForKey:@"CFBundleDisplayName"]
  };

  RNCallKeep *callKeep = [RNCallKeep allocWithZone: nil];

I also expose all callKeep events to the publicity:

extern NSString * const RNCallKeepHandleStartCallNotification;
extern NSString * const RNCallKeepDidReceiveStartCallAction;
extern NSString * const RNCallKeepPerformAnswerCallAction;
extern NSString * const RNCallKeepPerformEndCallAction;
extern NSString * const RNCallKeepDidActivateAudioSession;
extern NSString * const RNCallKeepDidDeactivateAudioSession;
extern NSString * const RNCallKeepDidDisplayIncomingCall;
extern NSString * const RNCallKeepDidPerformSetMutedCallAction;
extern NSString * const RNCallKeepPerformPlayDTMFCallAction;
extern NSString * const RNCallKeepDidToggleHoldAction;
extern NSString * const RNCallKeepProviderReset;
extern NSString * const RNCallKeepCheckReachability;
extern NSString * const RNCallKeepDidLoadWithEvents;

[sboily]

Probably superseded by #394

[manuquentin]

Thanks @Romick2005 I've merged #394 instead.
Feel free to open another PR if you think there is something missing.