Check unit tests for duration

Currently we have several uni tests that took a a long time. All that tests are annotated by tags to exclude them on local builds. The tags can be found in `TestQualifierTags`:
- `AT_SCALE`
- `REMOTE_ONLY`
- `TIME_CONSUMING`

We need to add a definition for the tags and how they should be used. Next to this we should check all tests that are tagged with one of the given tags if we can speed them up.