docs: add unit tests to build pipeline (#3427)

* Add testing step to to docs build pipeline
* Requires updating import structure in some place
* Add simple unit test to cover some logic with highlights

.github/workflows/deploy_docs.yml

@@ -92,6 +92,9 @@ jobs:
           poetry run tslab install --python=python3
           poetry run jupyter kernelspec list
 
+      - name: Run unit tests
+        # Run unit tests on the docs build pipeline
+        run: make tests
       - name: Lint Docs
         # This step lints the docs using the existing linting set up.
         # It should be very fast and should not require any external services.