Shows detailed source “About” page when adding 3rd-party sources

Allows users to preview sources before adding them to their AltStore.

AltStore/Sources/SourceDetailsComponents.swift

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+//
+//  SourceDetailsComponents.swift
+//  AltStore
+//
+//  Created by Riley Testut on 3/16/23.
+//  Copyright © 2023 Riley Testut. All rights reserved.
+//
+
+import UIKit
+
+import Roxas
+
+class TitleCollectionReusableView: UICollectionReusableView
+{
+    let label: UILabel
+    
+    override init(frame: CGRect)
+    {
+        let fontDescriptor = UIFontDescriptor.preferredFontDescriptor(withTextStyle: .largeTitle).withSymbolicTraits(.traitBold)!
+        let font = UIFont(descriptor: fontDescriptor, size: 0.0)
+        
+        self.label = UILabel(frame: .zero)
+        self.label.font = font
+        
+        super.init(frame: frame)
+        
+        self.addSubview(self.label, pinningEdgesWith: .zero)
+    }
+    
+    required init?(coder: NSCoder) {
+        fatalError("init(coder:) has not been implemented")
+    }
+}
+
+class ButtonCollectionReusableView: UICollectionReusableView
+{
+    let button: UIButton
+    
+    override init(frame: CGRect)
+    {
+        self.button = UIButton(type: .system)
+        self.button.translatesAutoresizingMaskIntoConstraints = false
+        
+        super.init(frame: frame)
+        
+        self.addSubview(self.button, pinningEdgesWith: .zero)
+    }
+    
+    required init?(coder: NSCoder) {
+        fatalError("init(coder:) has not been implemented")
+    }
+}
+
+class TextViewCollectionViewCell: UICollectionViewCell
+{
+    let textView = CollapsingTextView(frame: .zero)
+    
+    override init(frame: CGRect)
+    {
+        super.init(frame: frame)
+        
+        self.initialize()
+    }
+    
+    required init?(coder: NSCoder)
+    {
+        super.init(coder: coder)
+        
+        self.initialize()
+    }
+    
+    private func initialize()
+    {
+        self.textView.font = UIFont.preferredFont(forTextStyle: .body)
+        self.textView.isScrollEnabled = false
+        self.textView.isEditable = false
+        self.textView.isSelectable = true
+        self.textView.dataDetectorTypes = [.link]
+        self.contentView.addSubview(self.textView, pinningEdgesWith: .zero)
+    }
+    
+    override func layoutMarginsDidChange()
+    {
+        super.layoutMarginsDidChange()
+        
+        self.textView.textContainerInset.left = self.contentView.layoutMargins.left
+        self.textView.textContainerInset.right = self.contentView.layoutMargins.right
+    }
+}