Simplify complex implementations

Replace verbose, complex code structures with simpler, more readable alternatives. Prefer existing methods over inline complex logic, use built-in functions instead of manual implementations, and leverage modern Python features for cleaner code.

Examples of improvements:

• Replace complex conditionals with existing methods: if browser_session.is_file_input(element_node): instead of multi-line type checking
• Simplify string manipulation: script_content.replace('python', '').replace('', '') instead of complex split logic with potential IndexError
• Use dictionary dispatch instead of long if/elif chains for action mapping
• Leverage modern Python features like the walrus operator: if (last_action := self.step_results[-1]['actions'][-1])['is_done']

This approach reduces code complexity, improves maintainability, and makes the codebase more readable while preventing potential errors from overly complex implementations.