Method _init_input() is common for all templates (Product, Article, ...) - find a better approach to re-use this

[PyExplorer]

Based on discussion about new Article template.
_init_input()

   def _init_input(self):
        urls_file = self.args.urls_file
        if urls_file:
            response = requests.get(urls_file)
            urls = load_url_list(response.text)
            self.logger.info(f"Loaded {len(urls)} initial URLs from {urls_file}.")
            self.start_urls = urls
        else:
            self.start_urls = [self.args.url]
        self.allowed_domains = list(set(get_domain(url) for url in self.start_urls))