[AltStoreCore] Adds Pledge, PledgeReward, and PledgeTier

Allows us to cache pledges for current user, which can be used to determine if user has access to Patreon-only apps.

AltStoreCore/Model/Patreon/PatreonAccount.swift

@@ -0,0 +1,58 @@
+//
+//  PatreonAccount.swift
+//  AltStore
+//
+//  Created by Riley Testut on 8/20/19.
+//  Copyright © 2019 Riley Testut. All rights reserved.
+//
+
+import CoreData
+
+@objc(PatreonAccount)
+public class PatreonAccount: NSManagedObject, Fetchable
+{
+    @NSManaged public var identifier: String
+    
+    @NSManaged public var name: String
+    @NSManaged public var firstName: String?
+    
+    @NSManaged public var isPatron: Bool
+    
+    /* Relationships */
+    @nonobjc public var pledges: Set<Pledge> { _pledges as! Set<Pledge> }
+    @NSManaged @objc(pledges) internal var _pledges: NSSet
+    
+    private override init(entity: NSEntityDescription, insertInto context: NSManagedObjectContext?)
+    {
+        super.init(entity: entity, insertInto: context)
+    }
+    
+    init(account: PatreonAPI.UserAccount, context: NSManagedObjectContext)
+    {
+        super.init(entity: PatreonAccount.entity(), insertInto: context)
+        
+        self.identifier = account.identifier
+        self.name = account.name
+        self.firstName = account.firstName
+        
+//        if let patronResponse = response.included?.first
+//        {
+//            let patron = Patron(response: patronResponse)
+//            self.isPatron = (patron.status == .active)
+//        }
+//        else
+//        {
+//            self.isPatron = false
+//        }
+        self.isPatron = true
+    }
+}
+
+public extension PatreonAccount
+{
+    @nonobjc class func fetchRequest() -> NSFetchRequest<PatreonAccount>
+    {
+        return NSFetchRequest<PatreonAccount>(entityName: "PatreonAccount")
+    }
+}
+