refactor: extract add extension method

Author: KristianDD

lib/constants.ts

@@ -45,7 +45,6 @@ export const APK_EXTENSION_NAME = ".apk";
 export const AAB_EXTENSION_NAME = ".aab";
 export const HASHES_FILE_NAME = ".nshashes";
 export const TNS_NATIVE_SOURCE_GROUP_NAME = "TNSNativeSource";
-export const TNS_NATIVE_EXTENSIONS_GROUP_NAME = "TNSExtensions";
 export const NATIVE_SOURCE_FOLDER = "src";
 export const APPLICATION_RESPONSE_TIMEOUT_SECONDS = 60;
 export const NATIVE_EXTENSION_FOLDER = "extensions";