Incorrect reporting for test jobs with same identifier but different package name

[lbarcziova]

When there are 2 test jobs configured with the same identifier (and probably also no identifier), but different package_name, reporting can be incorrect and lead to a check being stuck in pending state, even when the DB (=>dashboard) has the correct (completed) state. This was reported by @lsm5 recently. We should probably implement a pre-check similar to this: https://github.com/packit/packit-service/blob/bcaa61270b920964d279d9610f98b7a8824fa9c4/packit_service/worker/checker/copr.py#L81