Search sensors in API by asset

[joshuaunity]

Description

Search sensors by asset ID

Look & Feel

How to test

Apply the asset_id query param to the sensors API http://localhost:5000/api/v3_0/sensors?page=1&per_page=10&asset_id=2

Simply put in the ID of any valid asset

Further Improvements

None

Related Items

This PR closes: #1209

---

• [x] I agree to contribute to the project under Apache 2 License.
• [x] To the best of my knowledge, the proposed patch is not based on code under GPL or other license that is incompatible with FlexMeasures