Extension: Have the ability to add Pausability

[Neotamandua]

Summary

Enable the ability to pause and unpause the smart contract. It should restrict token transfers while paused. Only the owner can suspend operations temporarily for maintenance or in case of an emergency.

Acceptance Criteria

• Include a pause function callable only by the owner.
• Include an unpause() function callable only by the owner.
• Update token transfer function to check the paused state. Transfers fail when the contract is paused.
• Emit Pause and Unpause events when the state changes.