[ADD] Search bar for BrowseView on iOS 15

AltStore/View Extensions/Modifiers.swift

@@ -0,0 +1,29 @@
+//
+//  Modifiers.swift
+//  SideStore
+//
+//  Created by Fabian Thies on 01.12.22.
+//  Copyright © 2022 SideStore. All rights reserved.
+//
+
+import SwiftUI
+
+extension View {
+    
+    @ViewBuilder func `if`<Content: View>(_ condition: Bool, transform: (Self) -> Content) -> some View {
+        if condition {
+            transform(self)
+        } else {
+            self
+        }
+    }
+    
+    
+    @ViewBuilder func searchable(text: Binding<String>, placeholder: String) -> some View {
+        if #available(iOS 15.0, *) {
+            self.searchable(text: text, prompt: Text(placeholder))
+        } else {
+            self
+        }
+    }
+}