[AltStoreCore] Refactors core AltStore logic into AltStoreCore framework

AltStoreCore will contain all shared AltStore code between AltStore and any app extensions. Initially, it includes all AltStore model logic.

AltStoreCore/Patreon/Benefit.swift

@@ -0,0 +1,27 @@
+//
+//  Benefit.swift
+//  AltStore
+//
+//  Created by Riley Testut on 8/21/19.
+//  Copyright © 2019 Riley Testut. All rights reserved.
+//
+
+import Foundation
+
+extension PatreonAPI
+{
+    struct BenefitResponse: Decodable
+    {
+        var id: String
+    }
+}
+
+public struct Benefit: Hashable
+{
+    public var type: ALTPatreonBenefitType
+    
+    init(response: PatreonAPI.BenefitResponse)
+    {
+        self.type = ALTPatreonBenefitType(response.id)
+    }
+}