Delete account

[Darvid-223]

As a registered user, I want to delete my account so that I can permanently remove my data from the platform.

Acceptance Criteria

• [x] Add an "Account Settings" page where users can manage their account.
• [x] Implement a "Delete Account" button on the Account Settings page.
• [x] Set up backend logic to handle account deletion requests.
• [x] Ensure that all user data, including posts and comments, are securely and permanently deleted.
• [x] Add a confirmation step to prevent accidental deletion.
• [x] Test the account deletion functionality to ensure it works as expected.