Reorganize AltStore project into UIKit and SwiftUI folders

AltStore/UIKit/My Apps/InstalledAppsCollectionHeaderView.swift

@@ -0,0 +1,44 @@
+//
+//  InstalledAppsCollectionHeaderView.swift
+//  AltStore
+//
+//  Created by Riley Testut on 3/9/20.
+//  Copyright © 2020 Riley Testut. All rights reserved.
+//
+
+import UIKit
+
+final 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.textLabel.accessibilityTraits.insert(.header)
+        
+        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")
+    }
+}