Added structure of integration tests for in_situ etl

[rstrange-scottlogic]

This includes an initial pass at creating an integration test framework for the in-situ data etl. It does not include any consideration for the CAMs calls.

It creates a cached version of the response to the open AQ call, updates to the code to respond to this cache, as well as adding the ability to override which cities will be used. The test removes any data for the test cities, creates the cached file, then calls the ETL pipeline. Finally it checks the data for the city, and asserts appropriately.

There will need to be more tests added which will be a separate PR, this only covers the initial structure of how these tests will run.

[github-actions[bot]]

☂️ Python Coverage

current status: ✅

Overall Coverage

Lines	Covered	Coverage	Threshold	Status
786	737	94%	80%	🟢

New Files

No new covered files...

Modified Files

File	Coverage	Status
air-quality-backend/scripts/run_in_situ_etl.py	96%	🟢
air-quality-backend/src/air_quality/etl/in_situ/openaq_dao.py	93%	🟢
TOTAL	94%	🟢

updated for commit: 619c4b8 by action🐍