Add support for rejecting cookies with explicit consent state

[Numair25]

Currently, the package only supports accepting cookies by setting a cookie with value 1. There is no option for users to explicitly reject cookies.

I would like to propose adding support for a "Reject" or "Decline" option.

Proposed approach:

• Add a "Reject" button alongside the existing "Allow cookies" button
• Store the decision in the same cookie:
  • 1 = accepted
  • 0 = rejected
• Treat both values as a "decision made", so the banner does not reappear
• Maintain backward compatibility by continuing to check for cookie existence

This would allow developers to:

• distinguish between accepted and rejected users
• conditionally load scripts based on consent
• improve compliance with stricter cookie requirements

I have already implemented a working version locally and would be happy to open a PR if this approach aligns with the package direction.