Refactoring: Consolidate file deletion into a separate function

Signed-off-by: Roopesh Chander <roop@roopc.net>

WireGuard/Shared/FileManager+Extension.swift

@@ -16,4 +16,14 @@ extension FileManager {
         }
         return sharedFolderURL.appendingPathComponent("lastActivatedTunnelLog.txt")
     }
+
+    static func deleteFile(at url: URL) -> Bool {
+        do {
+            try FileManager.default.removeItem(at: url)
+        } catch(let e) {
+            os_log("Failed to delete file '%{public}@': %{public}@", log: OSLog.default, type: .debug, url.absoluteString, e.localizedDescription)
+            return false
+        }
+        return true
+    }
 }