Add more test to oonidata related endpoints

[hynnot]

This PR is about the issue #911

Steps:

• Add ARGS parameter in the make test command
• Add E2E tests to list analysis endpoint
• Add E2E tests to list observations endpoint
• Add E2E tests to aggregate analysis endpoint
• Add E2E tests to aggregate observations endpoint
• Refactor to add two fixtures in conftest to set the since and until params.
• Create a decorator to pass to int the str probe_asn filter.

Notes:

• An issue is created for the future so as not to depend on sample data and the necessary data is provided in each test to test the expected behavior: Remove the dependency with the sample data in the tests #924

[hellais]

LGTM!