This pull request includes several changes to improve the handling of paused or stopped states in the browser_use module. The main focus is on refactoring the code to centralize the check for paused or stopped states and ensuring this check is consistently applied throughout the relevant methods.

Refactoring and state check improvements:

• Added a new method _check_if_stopped_or_paused to the Agent class in browser_use/agent/service.py to centralize the logic for checking if the agent is paused or stopped.
• Replaced individual checks for _stopped or _paused with calls to the new _check_if_stopped_or_paused method in the step method of browser_use/agent/service.py. [1] [2] [3]
• Updated the run method in browser_use/agent/service.py to include the new _check_if_stopped_or_paused method.
• Modified the multi_act method in browser_use/controller/service.py to accept a check_break_if_paused parameter and call this function at various points to ensure the paused state is checked. [1] [2] [3]

Other changes:

• Updated the import statements in browser_use/controller/service.py to include the Callable type.
• Changed the task description in the AgentController class in examples/features/pause_agent.py to open multiple websites in one action.