[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/Migrations/Policies/InstalledAppPolicy.swift

@@ -0,0 +1,58 @@
+//
+//  InstalledAppPolicy.swift
+//  AltStore
+//
+//  Created by Riley Testut on 1/24/20.
+//  Copyright © 2020 Riley Testut. All rights reserved.
+//
+
+import CoreData
+import AltSign
+
+@objc(InstalledAppToInstalledAppMigrationPolicy)
+class InstalledAppToInstalledAppMigrationPolicy: NSEntityMigrationPolicy
+{
+    override func createRelationships(forDestination dInstance: NSManagedObject, in mapping: NSEntityMapping, manager: NSMigrationManager) throws
+    {
+        try super.createRelationships(forDestination: dInstance, in: mapping, manager: manager)
+        
+        // Entity must be in manager.destinationContext.
+        let entity = NSEntityDescription.entity(forEntityName: "Team", in: manager.destinationContext)
+        
+        let fetchRequest = NSFetchRequest<NSManagedObject>()
+        fetchRequest.entity = entity
+        fetchRequest.predicate = NSPredicate(format: "%K == YES", #keyPath(Team.isActiveTeam))
+        
+        let teams = try manager.destinationContext.fetch(fetchRequest)
+        
+        // Cannot use NSManagedObject subclasses during migration, so fallback to using KVC instead.
+        dInstance.setValue(teams.first, forKey: #keyPath(InstalledApp.team))
+    }
+    
+    @objc(defaultIsActiveForBundleID:team:)
+    func defaultIsActive(for bundleID: String, team: NSManagedObject?) -> NSNumber
+    {
+        let isActive: Bool
+        
+        let activeAppsMinimumVersion = OperatingSystemVersion(majorVersion: 13, minorVersion: 3, patchVersion: 1)
+        if !ProcessInfo.processInfo.isOperatingSystemAtLeast(activeAppsMinimumVersion)
+        {
+            isActive = true
+        }
+        else if let team = team, let type = team.value(forKey: #keyPath(Team.type)) as? Int16, type != ALTTeamType.free.rawValue
+        {
+            isActive = true
+        }
+        else
+        {
+            // AltStore should always be active, but deactivate all other apps.
+            isActive = (bundleID == StoreApp.altstoreAppID)
+            
+            // We can assume there is an active app limit,
+            // but will confirm next time user authenticates.
+            UserDefaults.standard.activeAppsLimit = ALTActiveAppsLimit
+        }
+        
+        return NSNumber(value: isActive)
+    }
+}

AltStoreCore/Model/Migrations/Policies/StoreAppPolicy.swift

@@ -0,0 +1,25 @@
+//
+//  StoreAppPolicy.swift
+//  AltStore
+//
+//  Created by Riley Testut on 9/14/19.
+//  Copyright © 2019 Riley Testut. All rights reserved.
+//
+
+import CoreData
+
+@objc(StoreAppToStoreAppMigrationPolicy)
+class StoreAppToStoreAppMigrationPolicy: NSEntityMigrationPolicy
+{
+    @objc(migrateIconURL)
+    func migrateIconURL() -> URL
+    {
+        return URL(string: "https://via.placeholder.com/150")!
+    }
+    
+    @objc(migrateScreenshotURLs)
+    func migrateScreenshotURLs() -> NSCopying
+    {
+        return [] as NSArray
+    }
+}