feat(SPV-1419): manage contacts flow example with proper TOTP generation & validation

[wregulski]

This pull request includes significant changes to the TOTP generation and validation functionality, along with the addition of a new task for managing contacts. The most important changes include the removal of the old generate_totp task, the introduction of a new manage_contacts task, and updates to the TOTP validation method to improve clarity and functionality.

Task Management Changes:

• Removed the generate_totp task from examples/Taskfile.yml.
• Added a new manage_contacts task to examples/Taskfile.yml for demonstrating TOTP generation and validation scenarios.

Codebase Updates:

• Removed the old generate_totp.go file, which contained the previous TOTP generation logic.
• Added a new manage_contacts.go file, which includes a comprehensive example of managing contacts and TOTP verification between users. This file introduces new configuration structures, user setup, and verification flow functions.

TOTP Validation Improvements:

• Updated the ValidateTotpForContact method in internal/api/v1/user/totp/totp.go to rename parameters for better clarity, changing requesterPaymail to validatorContact.
• Updated the ValidateTotpForContact method in user_api.go to reflect the same parameter renaming for consistency and clarity.

Pull Request Checklist

• 📖 I created my PR using provided : CODE_STANDARDS
• 📖 I have read the short Code of Conduct: CODE_OF_CONDUCT
• 🏠 I tested my changes locally.
• ✅ I have provided tests for my changes.
• 📝 I have used conventional commits.
• 📗 I have updated any related documentation.
• 💾 PR was issued based on the Github or Jira issue.

[github-actions]

Manual Tests

💚 Manual testing by @chris-4chain resulted in success.