Add support for Apple Silicon

-Update classes to read correct Apple Silicon CPU sensor
-Update project to compile a Universal 2 binary. Upgraded Sparkle to 2.1.0 as that was the latest and supports ARM64.
-Add MacBookPro18,1 to Machines.plist

Sparkle.framework/Versions/B/PrivateHeaders/SUInstallerLauncher+Private.h

@@ -0,0 +1,29 @@
+//
+//  SUInstallerLauncher+Private.h
+//  SUInstallerLauncher+Private
+//
+//  Created by Mayur Pawashe on 8/21/21.
+//  Copyright © 2021 Sparkle Project. All rights reserved.
+//
+
+#ifndef SUInstallerLauncher_Private_h
+#define SUInstallerLauncher_Private_h
+
+#import <Sparkle/SUExport.h>
+
+// Chances are clients will need this too
+#import <Sparkle/SPUInstallationType.h>
+
+@class NSString;
+
+/**
+ Private API for determining if the system needs authorization access to update a bundle path
+ 
+ This API is not supported when used directly from a Sandboxed applications and will always return @c YES in that case.
+ 
+ @param bundlePath The bundle path to test if authorization is needed when performing an update that replaces this bundle.
+ @return @c YES if Sparkle thinks authorization is needed to update the @c bundlePath, otherwise @c NO.
+ */
+SU_EXPORT BOOL SPUSystemNeedsAuthorizationAccessForBundlePath(NSString *bundlePath);
+
+#endif /* SUInstallerLauncher_Private_h */