feat: use v2 curriculum data

[Sembauke]

• fix: update base URL to v2 across multiple services and views
• fix: simplify expectation for superBlockButtons in Learn Landing view test

Checklist:

• I have read and followed the contribution guidelines.
• I have read and followed the how to open a pull request guide.
• My pull request targets the main branch of the repo.
• I have tested these changes locally on my machine.

Closes #XXXXX