Use new endpoint for surface aggregation

[equinor-ruaj]

Short description

Use new aggregation endpoint for surface aggregation.

Pre-review checklist

• Read through all changes. No redundant print() statements, commented-out code, or other remnants from the development. 👀
• Make sure tests pass after every commit. ✅
• New/refactored code is following same conventions as the rest of the code base. 🧬
• New/refactored code is tested. ⚙
• Documentation has been updated 🧾

Pre-merge checklist

• Commit history is consistent and clean. 👌