#307 remove data point entity

Merge Request

🥅 Description

Since we now interact with the data point table only via manually written queries, we don't need a PanacheRepository anymore. That's why, we remove the entity and the Panache-stuff from the code.

📓 Checklist

• The code compiles without any warnings.
• I followed the code review checklist.
• The documentation has been added/updated.

🔗 Related Issues

• Related #307 (closed)