Adds VS App Center analytics + crash reporting

Currently tracks install, refresh, and update app events.

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

@@ -0,0 +1,21 @@
+// Copyright (c) Microsoft Corporation. All rights reserved.
+// Licensed under the MIT License.
+
+#import "MSLogWithNameAndProperties.h"
+
+@class MSEventProperties;
+@class MSMetadataExtension;
+
+@interface MSEventLog : MSLogWithNameAndProperties
+
+/**
+ * Unique identifier for this event.
+ */
+@property(nonatomic, copy) NSString *eventId;
+
+/**
+ * Event properties.
+ */
+@property(nonatomic, strong) MSEventProperties *typedProperties;
+
+@end