migrate from `unittest` to `pytest` structure.

[jGaboardi]

Lots of tests in the esda suite still actively use unittest -- we should migrate all those to the modern pytest structure.

• [x] test_adbscan.py – https://github.com/pysal/esda/pull/343
• [ ] test_crand.py
• [ ] test_gamma.py
• [ ] test_geary.py
• [ ] test_getisord.py
• [ ] test_join_counts.py
• [ ] test_lee.py
• [ ] test_ljc_bv.py
• [ ] test_ljc_mv.py
• [ ] test_ljc.py
• [ ] test_local_geary_mv.py
• [ ] test_local_geary.py
• [ ] test_losh.py
• [ ] test_map_comparison.py
• [ ] test_mixture_smoothing.py
• [ ] test_moran.py
• [ ] test_shape.py
• [ ] test_silhouette.py
• [ ] test_smaup.py
• [ ] test_smoothing.py
• [x] test_topo.py – https://github.com/pysal/esda/pull/341
• [x] test_util.py – https://github.com/pysal/esda/pull/341

[martinfleis]

Note that I've been gradually doing that when adding Graph support as I needed pytest's parametrisation in there.

[jGaboardi]

@martinfleis

Same Q for this issue --> https://github.com/pysal/esda/issues/308#issuecomment-2220663719

[martinfleis]

Same answer :)

[jGaboardi]

This is (of course) turning out to be a far more in-depth task than anticipated (when am I going to learn?). Going to spilt this out by file or groups of files.

xref #340