[ADD] News, Browse and Settings views ported to SwiftUI

This commit contains WIP SwiftUI versions of most of the views in SideStore.

AltStore/Helper/DateFormatterHelper.swift

@@ -0,0 +1,48 @@
+//
+//  DateFormatterHelper.swift
+//  SideStore
+//
+//  Created by Fabian Thies on 20.11.22.
+//  Copyright © 2022 Fabian Thies. All rights reserved.
+//
+
+import Foundation
+
+struct DateFormatterHelper {
+    
+    private static let appExpirationDateFormatter: DateComponentsFormatter = {
+        let dateComponentsFormatter = DateComponentsFormatter()
+        dateComponentsFormatter.zeroFormattingBehavior = [.pad]
+        dateComponentsFormatter.collapsesLargestUnit = false
+        return dateComponentsFormatter
+    }()
+    
+    
+    static func string(forExpirationDate date: Date) -> String {
+        let startDate = Date()
+        let interval = date.timeIntervalSince(startDate)
+        guard interval > 0 else {
+            return ""
+        }
+        
+        if interval < (1 * 60 * 60) {
+            self.appExpirationDateFormatter.unitsStyle = .positional
+            self.appExpirationDateFormatter.allowedUnits = [.minute, .second]
+        }
+        else if interval < (2 * 24 * 60 * 60)
+        {
+            self.appExpirationDateFormatter.unitsStyle = .positional
+            self.appExpirationDateFormatter.allowedUnits = [.hour, .minute, .second]
+        }
+        else
+        {
+            self.appExpirationDateFormatter.unitsStyle = .full
+            self.appExpirationDateFormatter.allowedUnits = [.day]
+            
+//            let numberOfDays = endDate.numberOfCalendarDays(since: startDate)
+//            text = String(format: NSLocalizedString("%@ DAYS", comment: ""), NSNumber(value: numberOfDays))
+        }
+        
+        return self.appExpirationDateFormatter.string(from: startDate, to: date) ?? ""
+    }
+}