[feat] Add Unit Tests, Lint, Documentation, and API v2 Updates for Main Page

[Aloento]

Summary of the Pull Request

This PR focuses on enhancing the main page with the following changes:

• API v2 Updates: Implement changes necessary to integrate the main page with API v2.
• Unit Tests: Add unit tests for main page functionality, including any complex logic to ensure robustness.
• Documentation: Update basic documentation related to the main page, including explanations of complex logic.

Notes:

• This is a smaller, focused PR to avoid large, difficult-to-review changes.
• Additional pages will follow in separate PRs with similar updates.

PR Checklist

• Refers to: https://github.com/orgs/opentelekomcloud-infra/projects/15?pane=issue&itemId=81702177
• Tests added/passed.
• Documentation updated.

Check Performed

Test Files  2 passed (2)
      Tests  2 passed (2)
   Start at  13:19:40
   Duration  12.13s (transform 638ms, setup 613ms, collect 12.95s, tests 3.19s, environment 2.24s, prepare 1.20s)

[SebastianGode]

Looks fine to me. While I currently can't build it without backend, the changes are fine.