[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/Model/AppID.swift

@@ -0,0 +1,52 @@
+//
+//  AppID.swift
+//  AltStore
+//
+//  Created by Riley Testut on 1/27/20.
+//  Copyright © 2020 Riley Testut. All rights reserved.
+//
+
+import Foundation
+import CoreData
+
+import AltSign
+
+@objc(AppID)
+public class AppID: NSManagedObject, Fetchable
+{
+    /* Properties */
+    @NSManaged public var name: String
+    @NSManaged public var identifier: String
+    @NSManaged public var bundleIdentifier: String
+    @NSManaged public var features: [ALTFeature: Any]
+    @NSManaged public var expirationDate: Date?
+    
+    /* Relationships */
+    @NSManaged public private(set) var team: Team?
+    
+    private override init(entity: NSEntityDescription, insertInto context: NSManagedObjectContext?)
+    {
+        super.init(entity: entity, insertInto: context)
+    }
+    
+    public init(_ appID: ALTAppID, team: Team, context: NSManagedObjectContext)
+    {
+        super.init(entity: AppID.entity(), insertInto: context)
+                
+        self.name = appID.name
+        self.identifier = appID.identifier
+        self.bundleIdentifier = appID.bundleIdentifier
+        self.features = appID.features
+        self.expirationDate = appID.expirationDate
+        
+        self.team = team
+    }
+}
+
+public extension AppID
+{
+    @nonobjc class func fetchRequest() -> NSFetchRequest<AppID>
+    {
+        return NSFetchRequest<AppID>(entityName: "AppID")
+    }
+}