Adds support for activating and deactivating apps

iOS 13.3.1 limits free developer accounts to 3 apps and app extensions. As a workaround, we now allow up to 3 “active” apps (apps with installed provisioning profiles), as well as additional “inactivate” apps which don’t have any profiles installed, causing them to not count towards the total. Inactive apps cannot be opened until they are activated.

AltStore/My Apps/InstalledAppsCollectionHeaderView.swift

@@ -0,0 +1,43 @@
+//
+//  InstalledAppsCollectionHeaderView.swift
+//  AltStore
+//
+//  Created by Riley Testut on 3/9/20.
+//  Copyright © 2020 Riley Testut. All rights reserved.
+//
+
+import UIKit
+
+class InstalledAppsCollectionHeaderView: UICollectionReusableView
+{
+    let textLabel: UILabel
+    let button: UIButton
+    
+    override init(frame: CGRect)
+    {
+        self.textLabel = UILabel()
+        self.textLabel.translatesAutoresizingMaskIntoConstraints = false
+        self.textLabel.font = UIFont.systemFont(ofSize: 24, weight: .bold)
+        
+        self.button = UIButton(type: .system)
+        self.button.translatesAutoresizingMaskIntoConstraints = false
+        self.button.titleLabel?.font = UIFont.systemFont(ofSize: 16, weight: .medium)
+        
+        super.init(frame: frame)
+        
+        self.addSubview(self.textLabel)
+        self.addSubview(self.button)
+        
+        NSLayoutConstraint.activate([self.textLabel.leadingAnchor.constraint(equalTo: self.layoutMarginsGuide.leadingAnchor),
+                                     self.textLabel.bottomAnchor.constraint(equalTo: self.bottomAnchor)])
+        
+        NSLayoutConstraint.activate([self.button.trailingAnchor.constraint(equalTo: self.layoutMarginsGuide.trailingAnchor),
+                                     self.button.firstBaselineAnchor.constraint(equalTo: self.textLabel.firstBaselineAnchor)])
+        
+        self.preservesSuperviewLayoutMargins = true
+    }
+    
+    required init?(coder: NSCoder) {
+        fatalError("init(coder:) has not been implemented")
+    }
+}