Add new Flag to every command to choose if we want to generate static members or not

Sources/ResgenSwift/Strings/Twine/TwineOptions.swift

@@ -28,6 +28,8 @@ struct TwineOptions: ParsableArguments {
     var extensionOutputPath: String
 }
 
+// MARK: - Private var getter
+
 extension TwineOptions {
     var langs: [String] {
         langsRaw
@@ -35,3 +37,22 @@ extension TwineOptions {
             .map { String($0) }
     }
 }
+
+// MARK: - Computed var
+
+extension TwineOptions {
+    var inputFilenameWithoutExt: String {
+        URL(fileURLWithPath: inputFile)
+            .deletingPathExtension()
+            .lastPathComponent
+    }
+    
+    var extensionFilePath: String {
+        "\(extensionOutputPath)/\(inputFilenameWithoutExt).swift"
+    }
+    
+    // "R2String+" is hardcoded in Twine formatter
+    var extensionFilePathGenerated: String {
+        "\(extensionOutputPath)/R2String+\(inputFilenameWithoutExt).swift"
+    }
+}