Adds VS App Center analytics + crash reporting

Currently tracks install, refresh, and update app events.

Pods/AppCenter/AppCenter-SDK-Apple/iOS/AppCenterAnalytics.framework/Headers/MSLogWithProperties.h

@@ -0,0 +1,20 @@
+// Copyright (c) Microsoft Corporation. All rights reserved.
+// Licensed under the MIT License.
+
+#ifndef MS_LOG_WITH_PROPERTIES_H
+#define MS_LOG_WITH_PROPERTIES_H
+
+#import <Foundation/Foundation.h>
+
+#import "MSAbstractLog.h"
+
+@interface MSLogWithProperties : MSAbstractLog
+
+/**
+ * Additional key/value pair parameters. [optional]
+ */
+@property(nonatomic, strong) NSDictionary<NSString *, NSString *> *properties;
+
+@end
+
+#endif