Move file-to-lines to String extension

Passepartout/Sources/Utils.swift

@@ -191,3 +191,13 @@ extension StringProtocol where Index == String.Index {
         return NSRange(range, in: self)
     }
 }
+
+extension String {
+    func trimmedLines() -> [String] {
+        return components(separatedBy: .newlines).map {
+            $0.trimmingCharacters(in: .whitespacesAndNewlines)
+        }.filter {
+            !$0.isEmpty
+        }
+    }
+}

Passepartout/Sources/VPN/TunnelKitProvider+FileConfiguration.swift

@@ -59,8 +59,7 @@ extension TunnelKitProvider.Configuration {
     }
     
     static func parsed(from url: URL) throws -> (String, TunnelKitProvider.Configuration) {
-        let content = try String(contentsOf: url)
-        let lines = content.components(separatedBy: .newlines).map { $0.trimmingCharacters(in: .whitespacesAndNewlines) }.filter { !$0.isEmpty }
+        let lines = try String(contentsOf: url).trimmedLines()
 
         var defaultProto: TunnelKitProvider.SocketType?
         var defaultPort: UInt16?