chore: improve dev-testing ergonomics

- [ ] improve dev control over test outputs (e.g., move `print` to `logging`/`logger`)
- [ ] improve test run speed (currently takes ~ 38 mins locally to run the full suite)
- [ ] convert unittest to pytest
- [ ] debug why `make test` ends up hanging after and forces users to cntrl-c:
```
----------------------------------------------------------------------
Ran 503 tests in 2309.364s

OK (skipped=94)
```
- [ ] move logging.info to logger.info as suggested by @dalito:

```
Maybe switch to a named logger as suggested here ([tutorial](https://docs.python.org/3/howto/logging.html#advanced-logging-tutorial) or [logging cookbook](https://docs.python.org/3/howto/logging-cookbook.html#logging-cookbook)).

To change insert after the import section

logger = logging.getLogger(__name__)
and then replace all logging.debug, ligging.info etc. by logger.debug, logger.info etc.

linkml-runtime also does it this way ([test_schemaview.py](https://github.com/linkml/linkml-runtime/blob/main/tests/test_utils/test_schemaview.py)).
````