Replace react-toast-notifications with react-hot-toast

[arshia-pourfar]

Description:
This pull request replaces the react-toast-notifications library with react-hot-toast to improve performance, provide a more modern user experience, and enable better customization options.
Key changes:

• Removed all dependencies and usage of react-toast-notifications
• Installed and integrated react-hot-toast
• Replaced all toast-related components and logic throughout the project
• Deleted obsolete files related to the previous toast system (snackbar/actions.ts, snackbar/signal.ts, etc.)
  Feel free to review and let me know if any adjustments are needed. Thanks!

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