[AltKit] Replaces dedicated AltKit module with shared files across targets

Treating AltKit as a full module resulted in more complexity than necessary, when we really just wanted to share some files between different targets. Now we can share individual files across modules as-needed without AltKit overhead.

Shared/Connections/ALTConnection.h

@@ -0,0 +1,23 @@
+//
+//  ALTConnection.h
+//  AltKit
+//
+//  Created by Riley Testut on 6/1/20.
+//  Copyright © 2020 Riley Testut. All rights reserved.
+//
+
+#import <Foundation/Foundation.h>
+
+NS_ASSUME_NONNULL_BEGIN
+
+NS_SWIFT_NAME(Connection)
+@protocol ALTConnection <NSObject>
+
+- (void)sendData:(NSData *)data completionHandler:(void (^)(BOOL, NSError * _Nullable))completionHandler NS_REFINED_FOR_SWIFT;
+- (void)receiveDataWithExpectedSize:(NSInteger)expectedSize completionHandler:(void (^)(NSData * _Nullable, NSError * _Nullable))completionHandler NS_SWIFT_NAME(__receiveData(expectedSize:completionHandler:));
+
+- (void)disconnect;
+
+@end
+
+NS_ASSUME_NONNULL_END