Extend find_all_hard_coded_references from models to tests

### Describe the feature
Currently one can easily use macro find_all_hard_coded_references to uncover hard-coded references for dbt models. For tests, this doesn't seem to be possible. It would be great to have the possibility to include dbt tests into the macro as well.

### Describe alternatives you've considered
I have tried to change evaluator code to consider both resource types, models AND tests but it didn't pan out.

### Additional context
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### Who will this benefit?
Anyone who wants to detect any kind of hard-coded references in their dbt project

### Are you interested in contributing this feature?
I would find contribution interesting but I would need some guidance on how to approach the implementation