nit: remove unused methods getTriggerValueForKey

* no longer used, dead code

Author: nan-li

iOS_SDK/OneSignalSDK/OneSignalInAppMessages/Controller/OSMessagingController.h

@@ -61,7 +61,6 @@ NS_ASSUME_NONNULL_BEGIN
 - (void)removeTriggersForKeys:(NSArray<NSString *> *)keys;
 - (void)clearTriggers;
 - (NSDictionary<NSString *, id> *)getTriggers;
-- (id)getTriggerValueForKey:(NSString *)key;
 
 - (void)addInAppMessageClickListener:(NSObject<OSInAppMessageClickListener> *_Nullable)listener;
 - (void)removeInAppMessageClickListener:(NSObject<OSInAppMessageClickListener> *_Nullable)listener;

iOS_SDK/OneSignalSDK/OneSignalInAppMessages/Controller/OSMessagingController.m

@@ -815,10 +815,6 @@ - (void)clearTriggers {
     return self.triggerController.getTriggers;
 }
 
-- (id)getTriggerValueForKey:(NSString *)key {
-    return [self.triggerController getTriggerValueForKey:key];
-}
-
 #pragma mark OSInAppMessageViewControllerDelegate Methods
 - (void)messageViewControllerDidDisplay:(OSInAppMessageInternal *)message {
     [self onDidDisplayInAppMessage:message];
@@ -1227,7 +1223,6 @@ - (void)addTriggers:(NSDictionary<NSString *, id> *)triggers {}
 - (void)removeTriggersForKeys:(NSArray<NSString *> *)keys {}
 - (void)clearTriggers {}
 - (NSDictionary<NSString *, id> *)getTriggers { return @{}; }
-- (id)getTriggerValueForKey:(NSString *)key { return 0; }
 #pragma mark OSInAppMessageViewControllerDelegate Methods
 - (void)messageViewControllerWasDismissed {}
 - (void)messageViewDidSelectAction:(OSInAppMessageInternal *)message withAction:(OSInAppMessageClickResult *)action {}

iOS_SDK/OneSignalSDK/OneSignalInAppMessages/Controller/OSTriggerController.h

@@ -52,7 +52,6 @@ NS_ASSUME_NONNULL_BEGIN
 - (void)addTriggers:(NSDictionary<NSString *, id> *)triggers;
 - (void)removeTriggersForKeys:(NSArray<NSString *> *)keys;
 - (NSDictionary<NSString *, id> *)getTriggers;
-- (id)getTriggerValueForKey:(NSString *)key;
 - (void)timeSinceLastMessage:(NSDate *)date;
 
 @end

iOS_SDK/OneSignalSDK/OneSignalInAppMessages/Controller/OSTriggerController.m

@@ -69,12 +69,6 @@ - (void)removeTriggersForKeys:(NSArray<NSString *> *)keys {
     }
 }
 
-- (id)getTriggerValueForKey:(NSString *)key {
-    @synchronized (self.triggers) {
-        return self.triggers[key];
-    }
-}
-
 /*
  * Part of redisplay logic
  *