Frontend: Add toast notifications for transactions

[EDOHWARES]

Description

When a user creates a task, they should see a toast notification indicating the transaction is pending, and then another when it succeeds or fails.

Requirements

• Integrate a toast library (e.g., react-hot-toast).
• Wire it up to the transaction submission logic.
• Include block explorer links in success toasts.

[Codekill33]

@Codekill33 has applied to work on this issue as part of the Stellar Wave Program's 6th wave.

Hi, I have experience with React and transaction flows, and I’ll integrate toast notifications for pending, successful, and failed transactions, including block explorer links in success toasts. Kindly assign me to this issue. Thank you

ETA - 8 hours

ℹ️ Repo Maintainers: To accept this application, review their application or assign @Codekill33 to this issue.