Refactoring/ios (#300)

iOS app refactoring (native part):
- connection bugs fixed
- improved stability 
- logs from network extension

client/platforms/ios/ios_controller_wrapper.mm

@@ -0,0 +1,28 @@
+#import "ios_controller_wrapper.h"
+#include "ios_controller.h"
+
+@implementation IosControllerWrapper
+
+- (instancetype)initWithCppController:(IosController *)controller {
+    self = [super init];
+    if (self) {
+        cppController = controller;
+    }
+    return self;
+}
+
+- (void)vpnStatusDidChange:(NSNotification *)notification {
+
+    NETunnelProviderSession *session = (NETunnelProviderSession *)notification.object;
+
+    if (session ) {
+        cppController->vpnStatusDidChange(session);
+    }
+}
+
+- (void) vpnConfigurationDidChange:(NSNotification *)notification {
+    cppController->vpnStatusDidChange(notification);
+}
+
+
+@end