feat(rln): implement membership management (extend, erase, withdraw)

[danisharora099]

Description

Users should be able to manage their RLN memberships by extending, erasing, and withdrawing deposits as needed.

User Story

• As a user, I want to extend my RLN membership before it expires, so that I can continue using the service.
• As a user, I want to erase my membership and withdraw my deposit, so that I can reclaim my funds.

Proposed Solution / Feature Design

• Fetch and display the user’s active memberships.
• Implement a button to extend an active membership (only available in the grace period).
• Allow users to erase their memberships and move them to ErasedAwaitsWithdrawal.
• Enable deposit withdrawals for erased memberships.

Optional: Diagram or Draft of Design

Notes

• Implement UI states based on the membership lifecycle.
• Ensure smart contract restrictions are followed (e.g., only holders can extend/erase).

[danisharora099]

Resolved